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46.2 should be delivered. An IP address and a port provide the means for two programs to hook up and start talking. Every communication needs a port on each machine; one side “listens” on a well-known port and the other side “connects” to that port, generating a random port of its own. Ports are represented by an integer number. Ports below 1024 are usually accessible only by programs running as root and are thus mostly reserved for system services and the like. /etc/services (46.2) lists most of the well-known ports used by the main system services. Finally, ICMP provides diagnostic and traffic control messages. ICMP is primarily used by applications such as ping and traceroute (46.4) to diagnose problems, check network status, and the like. Routers can also use ICMP to control traffic. —DJPH 46.2 /etc/services Is Your Friend After you’ve been dealing with Internet services for a while, you come to remember certain well-known port numbers off of the top of your head. SMTP (46.8) is port 25, HTTP is port 80, and so on. However, unless your memory is far better than mine, you won’t remember them all. Luckily, that’s part of what /etc/services is for. It’s a database of well-known ports with symbolic names; any program that can take a port number should be able to take the appropriate symbolic name instead. If you want to make sure your SMTP server is up, the following two commands are equivalent: % telnet localhost 25 % telnet localhost smtp The definitive database of well-known ports is currently available at http:// www.iana.org/assignments/port-numbers/. On most <strong>Unix</strong>es, /etc/services is just a snapshot taken at the time that version of that <strong>Unix</strong> was released. When installing new services, often you’ll want to tweak your local copy of /etc/services to reflect the new service, if it’s not already there, even if only as a reminder. The format of the /etc/services is simple: service name port/protocol aliases Comments within the file start with a pound sign (#). As an example, a few common entries from /etc/services: ftp-data 20/tcp #File Transfer [Default Data] ftp-data 20/udp #File Transfer [Default Data] ftp 21/tcp #File Transfer [Control] ftp 21/udp #File Transfer [Control] ssh 22/tcp #Secure Shell Login ssh 22/udp #Secure Shell Login telnet 23/tcp 938 Part VIII: Communication and Connectivity This is the Title of the Book, eMatter Edition Copyright © 2009 O’Reilly & Associates, Inc. All rights reserved.
46.3 telnet 23/udp smtp 25/tcp mail #Simple Mail Transfer smtp 25/udp mail #Simple Mail Transfer —DJPH 46.3 Status and Troubleshooting ifconfig can be used to configure network devices (44.8), but it also can be used to see the current network device configuration. ifconfig–a is very useful for this. Here’s some sample output on a FreeBSD machine: % ifconfig -a rl0: flags=8843 mtu 1500 inet 192.168.1.1 netmask 0xffffffc0 broadcast 192.168.1.255 inet 192.168.1.5 netmask 0xffffffff broadcast 192.168.1.255 inet 192.168.1.6 netmask 0xffffffff broadcast 192.168.1.255 inet 192.168.1.7 netmask 0xffffffff broadcast 192.168.1.255 ether 0a:5c:da:a3:53:11 media: autoselect (100baseTX ) status: active supported media: autoselect 100baseTX 100baseTX 10baseT/UTP 10baseT/UTP 100baseTX lo0: flags=8049 mtu 16384 inet 127.0.0.1 netmask 0xff000000 This shows two network devices: rl0, which is an Ethernet card, and lo0, which is the loopback device. rl0’s primary IP address is 192.168.1.1, and it has aliases (that is, it also answers to) 192.168.1.5 through 192.168.1.6. This also shows me that both network devices believe that they’re actively sending and receiving packets (UP) and shows various options set on each device. The output on Linux is slightly different, but similar enough to easily find the same information. Linux also adds a few statistics to its ifconfig output that otherwise require a netstat to see. Especially useful are packets received and transmitted: eth0 Link encap:Ethernet HWaddr 0a:5c:da:a3:53:11 inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:18999386 errors:28965 dropped:0 overruns:0 frame:28965 TX packets:33955631 errors:0 dropped:0 overruns:0 carrier:0 collisions:29132 txqueuelen:100 RX bytes:1496731954 (1.3 GiB) TX bytes:2477239809 (2.3 GiB) Interrupt:10 Base address:0xda00 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU:3924 Metric:1 RX packets:107211318 errors:0 dropped:0 overruns:0 frame:0 TX packets:107211318 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:2880669120 (2.6 GiB) TX bytes:2880669120 (2.6 GiB) This is the Title of the Book, eMatter Edition Copyright © 2009 O’Reilly & Associates, Inc. All rights reserved. Chapter 46: Connectivity 939
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THIRD EDITION UNIX POWER TOOLS Shel
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Table of Contents How to Use This B
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4. Interacting with Your Environmen
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8.7 Some GNU ls Features 161 8.8 A
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12.9 Finer Control on tail 243 12.1
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17.7 Get Back What You Deleted with
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21.7 offset: Indent Text 396 21.8 C
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26. System Performance and Profilin
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30.10 Running a Series of Commands
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34.19 Multiline Delete 692 34.20 Ma
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Part VII Extending and Managing You
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43.7 The () Subshell Operators 893
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48.5 What We Mean by DoS 973 48.6 B
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How to Use This Book Summary Boxes
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Preface A Book for Browsing Technic
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Cross-References If a cross-referen
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Here’s a list of authors and thei
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time, and the book looked to be dyi
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Acknowledgments for the Second Edit
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Part I I.Basic Unix Environment Par
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1.2 Unix is also important to power
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1.3 1.3 The Core of Unix In recent
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1.5 For example, one basic rule is
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1.6 syntax—as well as more featur
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1.8 But you’re a novice, and you
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1.10 You can add new directories to
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1.11 stay in touch. Therefore, you
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1.13 Table 1-1. Filename extensions
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1.14 not match a period; you have t
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1.15 To locate any file, we can giv
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1.16 tries to look up files relativ
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1.18 use the chgrp command to chang
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1.21 These three scripting language
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1.22 rcp scp This is a “remote cp
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Chapter 22 Getting Help 2.1 The man
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2.4 Output from whereis typically l
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2.5 2.5 How Unix Systems Remember T
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2.8 (Of course, you don’t need to
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2.9 When using the info command, if
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Chapter 3 3 Setting Up Your Unix Sh
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3.3 xterm -ls starts a login shell
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3.3 Korn shell The Korn shell is a
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3.5 Now wherever you need to know t
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3.8 somehost% vi .cshrc ...Make edi
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3.9 case 35.10 case "$-/${ENV_SET:-
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3.11 • If you use several kinds o
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3.14 3.13 Terminal Setup: Testing P
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3.17 On many systems, the command s
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3.19 Other shell variables (35.9) a
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3.20 $Id 39.5 .netrc Alisting of ho
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3.21 3.21 Make Your Own Manpages Wi
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3.22 less 12.3 % ls -l /usr/local/m
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3.22 Table 3-1. Important -man macr
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4.3 The default bash prompt is a go
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4.5 } # for ksh do_prompt() { date=
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4.6 # # Functions: # setprompt() {
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4.8 applefarm:/usr/elaineq/projects
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4.10 If you’re using tcsh, its sp
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4.11 The string \$ is replaced by a
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4.13 bash doesn’t need an if beca
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4.14 Because bash can run a command
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4.16 The prompt format is up to you
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4.17 Wow! ohh, big mouth, Mick Jagg
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4.19 Here’s a different sort of s
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5.2 5.2 The Idea of a Terminal Data
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5.3 5.3 Setting the Terminal Type W
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5.4 dialing in from home, but used
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5.5 The string Terminal recognized
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5.6 If you can log in after that, y
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5.6 sending data to your terminal.
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5.8 have, you know how disorienting
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5.10 xterm * gives you a window con
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5.13 5.12 How Many Lines to Save? I
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5.15 You can modify the character c
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5.17 Another quick way to get a lis
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5.18 5.18 Changing Fonts Dynamicall
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5.19 last selected text as a font n
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5.20 Figure 5-4. Text you copy from
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5.21 ${1+"$@"} 36.7 CTRL-d > This i
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5.23 5.23 Don’t Quote Arguments t
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6.1 Another example is if you mista
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6.2 One danger of using xmodmap is
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6.3 xclient*Buttons.foreground: xcl
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6.4 or nearly so. Among the less ob
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6.5 Anot-so-obvious principle behin
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6.7 6.6 Setting Resources with the
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6.8 will expect to read its data fr
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6.9 Use an editor to edit the file,
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6.10 Starting Remote X Clients from
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6.10 sapphire:joan % which rsh /bin
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Chapter 7 7 Directory Organization
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7.4 Reading a directory is relative
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7.7 Generally, a descriptive filena
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7.8 What if the parent directory do
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8.3 As long as we’re talking abou
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8.5 —JP jerry@ora ~/.bin 65 % ls
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8.6 you see the escape sequences wh
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8.7 The --color option gives you th
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8.10 —DS -rw------- 1 dansmith st
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8.11 The -C option lists the files
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8.13 % ls -b ab\013\014cd This show
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8.16 8.15 newer: Print the Name of
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Chapter 9 9 Finding Files with find
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9.2 -ls List the file’s name on s
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9.5 9.3 Don’t Forget -print “Wh
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9.6 • Takes the specified action
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9.9 9.8 Exact File-Time Comparisons
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9.10 % find . -inum 31246 -exec rm
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9.12 Let’s work from an example.
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9.15 9.14 Searching for Files by Si
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9.18 9.17 Duplicating a Directory T
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9.19 9.19 Wildcards with “Fast fi
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9.20 To make your own “fast find
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9.22 The answer is to add the Unix
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9.23 Here’s a practical example t
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9.24 To expand a range of members s
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9.27 Finally, let’s look at ./adi
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Chapter 10 10 Linking, Renaming, an
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10.3 The only time you actually nee
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10.4 ln -s /development/doc/man/man
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10.4 Links to a Directory While we
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10.6 To remove a link, either hard
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10.7 By using symlinks, we installe
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10.11 mv 'afile.new' 'afile.old' mv
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10.12 • Use this to copy the subd
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10.13 work bkup .setup - directory
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11.1 $ diff -e test1 test2 3c grape
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11.3 The diff3 command also has a -
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11.3 static char rcsid[] = + "$Id:
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11.6 To see only lines that are dif
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11.8 11.8 Comparing Two Files with
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11.9 11.9 More Friendly comm Output
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11.10 The basic operation that make
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11.11 password file is more recent
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12.2 1. First form: % cat file % ca
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12.4 Table 12-1. Commonly used less
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12.5 Next, od -c. It’s easier to
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12.7 /etc/magic has four fields: of
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12.10 ad0: 19569MB [39761/16/63] a
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12.11 enter CTRL-c (or whatever you
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Chapter 13 13 Searching Through Fil
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13.3 grep is also often used as a f
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13.6 % egrep "Alcuin (User|Programm
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13.7 rcsgrep, rcsegrep, rcsfgrep Th
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13.9 I’ve truncated each line for
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13.11 (Notice that as the problem g
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13.15 Ascript for looking up phone
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13.16 Well, as described on its own
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14.3 You really don’t care about
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14.5 14.4 Tricks for Making rm Safe
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14.8 —BB #!/bin/sh case $# in 0)
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14.11 14.10 Deletion with Prejudice
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14.14 14.13 Handling a Filename Sta
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14.16 The rmdir command often confu
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14.18 if 35.13 && 35.14 to a tempor
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Chapter 15 15 Optimizing Disk Space
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15.4 15.3 Save Space with “Bit Bu
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15.6 To eliminate core dumps entire
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15.6 gzip and gunzip can also compr
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15.7 common convention is .tgz. I
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15.8 This report shows information
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15.10 • Bigger than one block, si
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15.11 be repeated whenever you log
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Chapter 16 16 Spell Checking, Word
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16.2 default, the private dictionar
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16.4 When these spellers start, the
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16.5 =laserWrite =laserWrit =output
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16.6 16.6 Counting Lines, Words, an
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16.8 16.7 Find a a Doubled Word One
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16.9 deroff has one major failing,
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17.3 17.2 What We Cover The article
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17.4 17.4 Edits Between Files When
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17.7 17.6 Using Buffers to Move or
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17.9 Global Searches In vi you use
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17.13 You can combine ex line addre
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17.14 2. Replace one or more spaces
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17.17 $...$...\1 32.21 (You might
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17.18 As another example, assume yo
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17.20 17.20 Be Careful with vi -r R
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17.22 :!mail Read your mail. Be car
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17.23 abbr is an abbreviation for t
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17.26 You may be able to enforce co
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17.28 First, you’ll need the abso
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17.30 set nowrapscan wrapmargin=7 s
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18.2 Command Mode Maps The map comm
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18.3 What does that do? It executes
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18.4 2. Yank or delete the line(s)
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18.6 —JP Delete that long line in
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18.7 If you ask for a list of text-
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18.8 18.8 More Examples of Mapping
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18.11 Anytime you type (during text
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18.14 Here are two macros that cut
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Chapter 19 19 GNU Emacs 19.1 Emacs:
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19.2 Now that we all have nice work
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19.2 virtually every programming la
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19.4 First, try the command ESC-x r
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19.7 Along the same lines as comman
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19.10 Of course, now you’ll have
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19.11 1. Enter word-abbreviation mo
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Chapter 20 20 Batch Editing 20.1 Wh
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20.3 One additional suggestion is t
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20.4 delete [address] d [buffer] De
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20.6 20.5 Running Editing Scripts W
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20.7 is the directory on the local
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20.9 Unfortunately for programmers,
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20.10 For example, every Red Hat Li
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20.10 Except for BEGIN and END, pat
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20.10 Variables and Array Assignmen
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20.10 for for (item in array) comma
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20.10 format can also contain embed
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20.11 gawk Unfortunately, nawk is n
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21.2 21.2 Neatening Text with fmt O
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21.3 (37.4) and nroff. Using those
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21.5 # Get comment characters used
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21.8 writes to standard output. The
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21.9 split total 288 -r--r--r-- 1 j
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21.10 my $outfile; open($outfile, "
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21.10 There’s still a slight prob
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21.11 Of course, you need to be car
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21.12 uuencoding The uuencode utili
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21.12 Unlike uuencoded messages, wh
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21.15 The order of the columns and
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21.16 The columns aren’t balanced
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21.17 21.17 Straightening Jagged Co
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21.19 21.19 Joining Lines with join
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21.21 To show which names appear mo
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Chapter 22 22 Sorting 22.1 Putting
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22.2 field 3, continue sorting on f
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22.4 • Any whitespace character f
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22.6 1 11 12 2 ... Of course, this
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22.7 example, imagine you have a pr
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22.8 If you want more control over
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Chapter 23 23 Job Control 23.1 Job
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23.2 Some systems, like Linux, exte
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23.3 In fact, one job number is ass
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23.4 This may strike you as a defec
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23.7 If your system has job control
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23.10 background jobs that try to w
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23.12 PID TTY STAT TIME COMMAND 289
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23.13 23.13 Stopping Remote Login S
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Chapter 24 24 Starting, Stopping, a
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24.3 24.3 Managing Processes: Overa
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24.4 One more useful concept: when
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24.5 By default, ps lists only your
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24.6 The columns hold the username,
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24.7 Figure 24-1. Background jobs i
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24.9 24.9 The /proc Filesystem In U
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24.9 For a simple example, here’s
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24.9 cache size: 128 KB fdiv_bug: n
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24.11 came when the kernel detected
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24.13 • Processes waiting for una
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24.14 kill 24.12 % kill -HUP 4363 .
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24.15 kill is a shell builtin kill
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24.16 zap Amore flexible way to kil
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24.18 exec 36.5 —JP If that happe
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24.20 unique name and any value you
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24.21 To override the default shell
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24.22 to open its menus (5.17). If
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24.22 #!/bin/sh pidfile=/tmp/.nup-p
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25.2 • For processes that only ne
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25.2 If the first character in an e
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25.2 In case you’re curious, thes
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25.5 25.4 Including Standard Input
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25.8 Note that atq has no objection
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25.9 foreach 28.9 —JP % foreach n
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26.1 System performance degrades wh
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26.2 26.2 Timing Programs Two comma
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26.3 tee 43.8 stty lesleys ttypa 0.
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26.5 On most systems, no user can d
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26.5 System V C Shell nice System V
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Part VI VI.Scripting Part VI contai
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27.2 • File permissions are set i
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27.3 Shell Search Paths As article
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27.5 ures out that an input file an
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27.7 Searching the path (27.6) take
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27.8 But there’s a loophole. The
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27.10 What if you want the external
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27.11 % unalias unalias foo unalias
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27.12 You also need to know how man
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27.12 Multiline Quoting Once you ty
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27.13 How Quoting Works Table 27-2
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27.16 This command will display eac
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27.17 ter that is also used by the
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27.17 Table 27-3. Special character
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27.18 27.18 How Many Backslashes? T
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Chapter 28 Saving Time on the Comma
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28.3 After the interruption, I just
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28.4 • In zsh, {} also understand
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28.5 • :g makes the operation glo
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28.6 General Example: Filename Comp
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28.6 MH mail folders can be stored
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28.8 28.8 Repeating Commands Let’
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28.9 cat - 12.2 Press RETURN to see
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28.11 —JP 28.11 Repeating a Time-
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28.13 Here’s an example with zsh,
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28.14 The -l option lists each file
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28.16 As an example, here’s a ser
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28.17 Then xargs would run all of t
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28.18 Dialback It is surprising how
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28.18 Expect comes with several exa
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29.3 Note that aliases are not pass
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29.4 This alias has two arguments:
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29.6 29.6 zsh Aliases zsh has the r
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29.8 Alias options You aren’t lim
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29.10 • Renames any old prog file
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29.11 sed -n '/^;; ANSWER SECTION:/
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29.11 fac.sh The fac function calcu
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29.13 function, make an alias with
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29.13 to FPATH if it doesn’t find
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29.13 zsh The zsh system is mostly
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29.14 Here’s the same cps—store
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30.2 Most shells—except the origi
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30.5 In the first command line (co)
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30.7 $ rm !20:$ rm /tmp/0444-diff.t
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30.8 % echo xy xy % !:s/xy/yx echo
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30.8 This alias will pipe the outpu
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30.9 —DR In this example, we told
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30.12 30.12 Picking Up Where You Le
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30.13 ing numbers, so it can be rea
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30.14 you want to; its original ver
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30.14 "^X^D" -> list-choices-raw Ar
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30.14 There’s a complete list of
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30.16 An obvious point: you can set
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31.2 31.2 Using Relative and Absolu
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31.3 31.3 What Good Is a Current Di
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31.5 The current directory has i-nu
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31.7 break terminates the loop and
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31.8 The dirs command prints the di
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31.10 In the next example, trying t
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31.12 In fact, using echo (27.5) yo
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31.13 where the .global_enter file
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32.2 • Chapter 20, Batch Editing
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32.3 second character in the string
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32.5 [The situation is complicated
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32.7 32.7 Regular Expressions: Matc
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32.11 At first glance, it might see
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32.13 32.13 Regular Expressions: Re
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32.16 directory tree beneath it. IM
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32.17 32.17 Just What Does a Regula
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32.19 However, the pattern ends up
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32.21 Table 32-5. Valid metacharact
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32.21 with a large complement of GN
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32.21 Table 32-10. Search and repla
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33.2 • Wildcards can appear in an
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33.3 Table 33-1. Filename wildcards
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33.4 Some versions of tar understan
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33.6 33.6 Getting a List of Matchin
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33.8 #!/bin/sh case $# in vgrep 0|1
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Chapter 34 The sed Stream Editor 34
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34.4 Given filenames, sed will read
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34.5 runsed only modifies a file if
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34.6 An exclamation mark following
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34.9 When either the search pattern
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34.11 The ampersand makes it possib
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34.13 Note that without the numeric
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34.14 Look at the script: /^/H /^/
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34.15 s/.*the $.*$ statement.*/\1
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34.16 In this example, we know wher
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34.17 It excludes the last line ($)
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34.18 For instance, the N command t
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34.19 The core of the script is bas
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34.20 Because program examples are
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34.22 always-true s///.” Try the
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Chapter 35 Shell Programming for th
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35.2 35.2 Everyone Should Learn Som
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35.3 • Test a program’s exit st
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35.3 printenv env By convention, th
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35.5 PRINTER (45.4) or LPDEST can b
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35.6 35.6 The PATH Environment Vari
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35.8 In PATH, an empty entry (::) s
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35.9 Just as some programs use cert
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35.11 Here are more details about h
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35.13 bash and zsh have a handy way
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35.14 #!/bin/sh if cp "$1" "$1.bak"
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35.16 catsaway /dev/null 43.12 Loop
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35.17 case $# in 1) gzcat "$1" >$te
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35.19 35.19 Shell Script “Wrapper
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35.20 The third argument has a perf
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35.22 The first pass through the fo
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35.23 35.23 Loop Control: break and
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35.25 The first argument to set, --
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35.25 If the first parameter you se
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35.27 Be sure to leave space betwee
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35.30 35.30 Using Shell Functions i
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35.30 —SJC echo "couldn't find MX
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36.2 • Next is an assortment of a
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36.4 Let’s run both commands and
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36.6 exec also manipulates file des
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36.8 Several Bourne-type shells hav
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36.11 The portable way to unset all
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36.13 The dirname command strips th
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36.15 When the Unix kernel starts a
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36.16 36.16 n>&m: Swap Standard Out
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36.16 $ var=`grep "Joe" afone bfoen
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36.18 36.18 Shell Scripts On-the-Fl
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36.21 36.21 Quick Reference: expr e
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36.22 Truncate $x if it contains fi
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36.23 Notice that the inner double
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36.24 I want the number 99 from the
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36.25 36.25 Testing Two Strings wit
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36.27 (Here’s a fun enhancement,
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36.27 But if the lockfile is read-o
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37.1 Do you want to save the debugg
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37.4 The zero trick doesn’t work
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37.5 For the special case of iterat
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37.7 Unix’s internal routines com
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37.9 37.9 Making an Arbitrary-Size
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Chapter 38 - 38 Backing Up Files 38
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38.3 Accidents and oversights happe
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38.5 backups (of the files on your
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38.5 can then use tar again to add
Page 835 and 836:
38.6 many bytes to achieve compress
Page 837 and 838:
38.7 But the best solution is never
Page 839 and 840:
38.9 The answer I came up with was
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38.10 GNU tar Here’s another subt
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38.11 Here’s an example. We’re
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38.13 In this command, keepout goes
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38.14 Note also that full-scale bac
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39.2 39.2 Using tar to Create and U
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39.2 mt/mt.o mt/mt On some tars, if
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39.3 No extraction is being done he
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39.5 developers from around the wor
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39.6 This brief overview left out a
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39.8 which cvsroot you used for a p
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39.8 sees that the copy in the repo
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40.1 Table 40-1. FHS root subdirect
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40.5 makefile is modified to fit th
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40.5 Figure 40-2. Choosing the acce
Page 869 and 870:
40.5 Figure 40-3. The introduction
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40.5 Figure 40-6. The dependency re
Page 873 and 874:
40.6 The host part of the URI and t
Page 875 and 876:
40.7 The default use of wget downlo
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40.10 40.9 Installation with FreeBS
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Chapter 41 41 Perl 41.1 High-Octane
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41.3 Characteristics of this binary
Page 883 and 884:
41.4 Example 41-1. A sample Perl sc
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41.5 Perl allows for user defined s
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41.5 Table 41-3. Numerical operator
Page 889 and 890:
41.5 tioned: @INC and @ARGV. Since
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41.5 Example 41-7. Iterating over a
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41.6 Sometimes you need to iterate
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41.7 Table 41-8. Common Perl regula
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41.8 One advantage Perl has over sh
Page 899 and 900:
41.9 This section hardly scratched
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41.10 41.10 Perl Boot Camp, Part 7:
Page 903 and 904:
41.11 The CPAN module also has an i
Page 905 and 906:
41.12 41.12 Make Custom grep Comman
Page 907 and 908:
41.13 $content will be empty, and t
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Chapter 42 42 Python 42.1 What Is P
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42.3 Modules that are not packaged
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42.3 If you use functions like map(
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42.3 Given that a Python module is
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42.6 urllib also provides a functio
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42.9 To get to information submitte
Page 921:
42.10 plex the system you’re tryi
Page 925 and 926:
Chapter 43 43 Redirecting Input and
Page 927 and 928: 43.1 Be aware that: • While stand
Page 929 and 930: 43.4 the background, save the outpu
Page 931 and 932: 43.5 The better way to do this is t
Page 933 and 934: 43.7 The noclobber variable has one
Page 935 and 936: 43.10 43.9 How to tee Several Comma
Page 937 and 938: 43.11 43.11 Named Pipes: FIFOs mkfi
Page 939 and 940: 43.12 • Empty another file. Just
Page 941 and 942: 44.2 # FreeBSD atapci0: port 0xffa
Page 943 and 944: 44.4 CONFIG_BLK_DEV_IDEPCI=y CONFIG
Page 945 and 946: 44.5 own filesystems with a forest
Page 947 and 948: 44.7 Then, as a normal user in grou
Page 949 and 950: 44.10 For more details on NFS on yo
Page 951 and 952: 44.13 Platforms that provide a user
Page 953 and 954: 44.14 FreeBSD’s handbook has a ch
Page 955 and 956: 45.2 The first few articles in this
Page 957 and 958: 45.3 The message on lp indicates th
Page 959 and 960: 45.5 There are two ways to choose a
Page 961 and 962: 45.6 -m Merge files, printing one i
Page 963 and 964: 45.9 45.8 Printing Over a Network S
Page 965 and 966: 45.10 45.10 Introduction to Typeset
Page 967 and 968: 45.12 45.12 Typesetting Manpages: n
Page 969 and 970: 45.14 Much like the nroff input ear
Page 971 and 972: 45.16 Here’s an example of using
Page 973 and 974: 45.19 subjects. Don’t be fooled b
Page 975 and 976: 45.19 There are far too many progra
Page 977: 46.1 IP identifies machines through
Page 981 and 982: 46.4 This shows us the address (A)
Page 983 and 984: 46.6 46.6 Secure Shell (SSH) telnet
Page 985 and 986: 46.9 sendmail is the most well know
Page 987 and 988: 46.10 % dig oreilly.com ns ... ;; A
Page 989 and 990: 46.12 into the correct private addr
Page 991 and 992: Chapter 47 47 Connecting to MS Wind
Page 993 and 994: 47.2 [global] workgroup = MYGROUP ;
Page 995 and 996: 47.3 47.3 Securing Samba The topic
Page 997 and 998: 47.4 Figure 47-1. SWAT’s globals
Page 999 and 1000: 47.7 47.6 Connecting to SMB Shares
Page 1001 and 1002: 47.7 Figure 47-2. Unix VNC client c
Page 1003 and 1004: 47.9 47.9 Citrix: Making Windows Mu
Page 1005 and 1006: 47.9 Figure 47-4. Creating a new en
Page 1007: Part IX IX.Security Part IX contain
Page 1010 and 1011: 48.2 How many times have you accide
Page 1012 and 1013: 48.4 48.4 What We Mean by Buffer Ov
Page 1014 and 1015: 48.6 How simple is it to access con
Page 1016 and 1017: 48.6 Within FreeBSD and other Unix
Page 1018 and 1019: 48.8 You can search for modified fi
Page 1020 and 1021: 48.11 48.11 Disallow rlogin and rsh
Page 1022 and 1023: Chapter 49 Root, Group, and User Ma
Page 1024 and 1025: 49.3 In Linux, Solaris, and other s
Page 1026 and 1027: 49.6 How does Unix determine what g
Page 1028 and 1029:
49.7 $ ls -ln total 37 -rw-r--r-- 1
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49.9 However, a quick check shows t
Page 1032 and 1033:
49.12 Examples of aliases are: User
Page 1034 and 1035:
Chapter 50 File Security, Ownership
Page 1036 and 1037:
50.2 The first character in the ls
Page 1038 and 1039:
50.3 Which Group is Which? Since gr
Page 1040 and 1041:
50.5 50.5 Using chmod to Change Fil
Page 1042 and 1043:
50.7 That means “for all files (*
Page 1044 and 1045:
50.10 I couldn’t write the file u
Page 1046 and 1047:
50.11 This setup can still be a lit
Page 1048 and 1049:
50.12 md5sum The easy way is to com
Page 1050 and 1051:
50.15 If you need to change ownersh
Page 1052 and 1053:
51.3 SSH works by authenticating th
Page 1054 and 1055:
51.5 Q: How do I authenticate witho
Page 1056 and 1057:
51.5 Q: Trusted-host authentication
Page 1058 and 1059:
51.5 Q: Public-key authentication i
Page 1060 and 1061:
51.6 Q: Each time I run ssh-keygen,
Page 1062 and 1063:
51.7 Q: I changed the sshd config f
Page 1064 and 1065:
51.7 Q: ssh1 prints “Cannot fork
Page 1066 and 1067:
51.7 Don’t rely on shell quirks a
Page 1068 and 1069:
51.7 To fix this problem, be sure y
Page 1070 and 1071:
Glossary AIX A version of Unix from
Page 1072 and 1073:
flag flag In programming, a flagvar
Page 1074 and 1075:
portable Sun OS also provide “nam
Page 1076 and 1077:
word word Similar to a word in a sp
Page 1078 and 1079:
\ (backslash) \< \> (regular expres
Page 1080 and 1081:
# (hash mark) (continued) in commen
Page 1082 and 1083:
agents -agent option, ssh, 799 comp
Page 1084 and 1085:
awk utility (continued) line-number
Page 1086 and 1087:
ind (Berkeley Internet Name Daemon)
Page 1088 and 1089:
checksed script, 671 chess script,
Page 1090 and 1091:
in .logout file, 89 logout file, cr
Page 1092 and 1093:
with vi editor, 313 xclipboard, usi
Page 1094 and 1095:
functions calling functions, 583-58
Page 1096 and 1097:
df command, 501 output, parsing wit
Page 1098 and 1099:
dump command arguments, correct ord
Page 1100 and 1101:
AT, 54 CBLKWID (comment block width
Page 1102 and 1103:
exiting directories, automatic setu
Page 1104 and 1105:
searching by column, using awk, 258
Page 1106 and 1107:
anonymous FTP server, configuring,
Page 1108 and 1109:
hardware, 900 dialup PPP sessions,
Page 1110 and 1111:
inheritance process information, 45
Page 1112 and 1113:
daemons, 14-16 modules for device d
Page 1114 and 1115:
linkname, ln command and, 208 links
Page 1116 and 1117:
in shell functions, 581 loosely typ
Page 1118 and 1119:
methods, 844 Python, 873 Microsoft
Page 1120 and 1121:
as argument separators, 527 awk pro
Page 1122 and 1123:
| in extended regular expressions,
Page 1124 and 1125:
processes, 974 swap space, 975 virt
Page 1126 and 1127:
converting source files, 932 lp and
Page 1128 and 1129:
checking current processes for secu
Page 1130 and 1131:
shell output and errors into tempor
Page 1132 and 1133:
login utility, 141 disabling for se
Page 1134 and 1135:
in .cshrc.$HOST file, 60 FPATH (for
Page 1136 and 1137:
unning commands at, 90 multiline co
Page 1138 and 1139:
edirecting standard I/O (see redire
Page 1140 and 1141:
into fields, 766 SPOOL (Simultaneou
Page 1142 and 1143:
success or failure of commands, ind
Page 1144 and 1145:
history (see history of commands) l
Page 1146 and 1147:
timing programs, 503 tip program, 5
Page 1148 and 1149:
values, Python objects, 873 /var di
Page 1150 and 1151:
newline character, 27 removing from
Page 1152 and 1153:
xmodmap program, 105, 127 defining
Page 1154 and 1155:
1114 Index This is the Title of the
Page 1156:
David Futato designed the interior
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