Mac OS X Leopard - ARCAism

Now this is just the first page of the man page—you can scroll through the rest using either
the arrow keys (to move up and down one line at a time), or the spacebar to move through one
page at a time. When you are done, you can exit the man page by pressing Q on the keyboard.
grep
TIP Computers have come a long way since the man page system was created, and while
reading a man page in the terminal is relatively easy for short and simple commands, for more
complex commands that can scroll through 100 or more screens, this isn’t ideal. One neat trick
you can use is man -t command | open -f -a /Applications/Preview.app, which will open the
entire man page of the command in Preview as a PDF file for immediate reading, printing, or
saving. (The -t option converts the man page into a PostScript file, which you can then pipe
into your Preview application, which converts the PostScript file into a PDF file as it opens it.
Pipes are covered later.)
The grep command searches through files or results for a specified string and then prints out the
lines that contain a match. For example, using the preceding text file, we could print out all lines
that contain “to” using the command grep to tomorrow. This is shown here:
ln
Leopard:~/Documents/Shakespeare scott$ ls
nothing tomorrow
Leopard:~/Documents/Shakespeare scott$ grep to tomorrow
Tomorrow, and tomorrow, and tomorrow,
Creeps in this petty pace from day to day
The way to dusty death. Out, out, brief candle!
ln is the command-line utility for creating links. While there are different ways of linking files,
what we are most concerned with are symbolic (a.k.a. soft) links (more commonly referred to as
aliases, or shortcuts in Windows). To create a symbolic link, you use ln with the -s link, followed
by the name of the source file and then optionally the name of the linked file.
NOTE ln by default creates a hard link, which is most likely not what you want, so it’s important
to remember the -s option. For the technically curious, a hard link essentially creates a
new file that shares its data with another (the source). If you edit one, the data will change in
the other. If you delete one, the other will still remain with all the data intact. A symbolic link,
on the other hand (like an alias or shortcut), creates a special “path” file that always refers to
the original. If this original is deleted, the path is broken unless a new file of the same name
replaces the original. A big difference in use is that a symbolic link can refer to a directory or a
file on a different file system, while a hard link cannot.
Let’s look at ln in action:
CHAPTER 18 INTRODUCING DARWIN AND THE SHELL 301
Leopard:~/Documents/Shakespeare scott$ ls
macbeth/ nothing
Leopard:~/Documents/Shakespeare scott$ ls macbeth/
soliloqy4
Leopard:~/Documents/Shakespeare scott$ ln -s macbeth/soliloquy4 tomorrow
Leopard:~/Documents/Shakespeare scott$ ls
macbeth/ nothing tomorrow@
Leopard:~/Documents/Shakespeare scott$ cat tomorrow
Tomorrow, and tomorrow, and tomorrow,
Creeps in this petty pace from day to day
To the last syllable of recorded time,