Mac OS X Leopard - ARCAism

less (more)
less is a pager, which allows you to scroll through large amounts of text that may normally
scroll right by you in the terminal. You learned how pagers worked with the man command,
which automatically runs in a pager (which by default in Leopard is actually less)—however,
sometimes it’s useful to use a pager with other commands as well. For example, when we use the
ps aux command, we are presented with lots of information scrolling right by; however, if we
pipe the ps aux command into less, then we can scroll around our output just as we scrolled
around our man pages. An example of this is the following:
Leopard:~ scott$ ps aux | less
USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME COMMAND
scott 304 5.9 -8.1 795272 170688 ?? S 8:15PM 24:06.93 /Applicati
root 39 0.7 -0.3 30440 6192 ?? Ss 4:14PM 0:05.56 /usr/sbin/
windowse 62 0.1 -2.2 902716 45600 ?? Ss 4:14PM 5:30.36 /System/Li
scott 307 0.1 -0.6 372104 12548 ?? S 8:17PM 1:10.59 /Applicati
root 31 0.0 -0.1 27840 2408 ?? Ss 4:14PM 0:00.03 /usr/bin/W
root 32 0.0 -0.4 303152 7440 ?? Ss 4:14PM 0:01.47 /Library/A
root 33 0.0 -0.1 27824 2052 ?? Ss 4:14PM 0:00.01 /System/Li
root 34 0.0 -0.1 27844 2328 ?? Ss 4:14PM 0:00.02 /usr/sbin/
root 35 0.0 -0.1 28564 2696 ?? Ss 4:14PM 0:00.82 /usr/sbin/
root 36 0.0 -0.1 27580 1088 ?? Ss 4:14PM 0:00.47 /usr/sbin/
root 37 0.0 -0.0 27288 1016 ?? Ss 4:14PM 0:00.08 /usr/sbin/
root 40 0.0 -0.3 31852 5772 ?? Ss 4:14PM 0:00.23 /usr/sbin/
root 41 0.0 -0.1 27776 2780 ?? Ss 4:14PM 0:00.12 /usr/sbin/
root 42 0.0 -0.1 28324 1716 ?? Ss 4:14PM 0:00.02 /usr/sbin/
root 44 0.0 -0.3 29268 5316 ?? Ss 4:14PM 0:00.27 /usr/sbin/
root 46 0.0 -0.0 27864 880 ?? Ss 4:14PM 0:00.15 /usr/sbin/
root 50 0.0 -0.0 27252 708 ?? Ss 4:14PM 0:20.84 /usr/sbin/
root 54 0.0 -0.3 30744 6768 ?? Ss 4:14PM 0:00.32 /usr/sbin/
root 55 0.0 -0.1 27676 2184 ?? Ss 4:14PM 0:00.37 /usr/sbin/
root 63 0.0 -0.3 37828 5512 ?? S 4:14PM 0:00.18 /usr/sbin/
root 64 0.0 -0.5 37028 9752 ?? Ss 4:14PM 0:00.53 /System/Li
scott 69 0.0 -0.4 82936 8332 ?? Ss 4:15PM 0:02.26 /System/Li
:
Using the arrow keys, we can now scroll through our output, and when we are done, we can
quit the pager and return to our prompt by pressing Q.
NOTE Another older yet extremely popular pager was called more. Although more was very
popular, it was lacking in many ways—for instance, it would only allow you to scroll down (e.g.,
you couldn’t go back once you scrolled past something). Because of this, less has largely
replaced more; however, for backward compatibility, the more command has been linked with
less, so the more command still works (although it will actually run less).
find and whereis
CHAPTER 18 INTRODUCING DARWIN AND THE SHELL 305
find and whereis are two commands that work very differently, yet are both used to the same
ends: finding something in the Darwin file system.
find by default takes a path variable and presents a list of matches. Additionally, if a match
is a directory, find will traverse that directory as well (find / will return every visible file on your
hard drive!). Using regular expressions and wildcards can effectively narrow (or broaden) your
search as needed. A simple find example may be something like this: