In this chapter, we’ve seen a few of the many uses of regular expressions. We can find even more if we use regular expressions to search for additional applications that use them. We can do that by searching the man pages:
cd /usr/share/man/man1[me@linuxbox man1]$
zgrep -El 'regex|regular expression' *.gz
zgrep program provides a frontend for
grep, allowing it to read compressed files. In our example, we search the compressed Section 1 man page files in their usual location. The result of this command is a list of files containing the string
regular expression. As we can see, regular expressions show up in a lot of programs.
There is one feature found in basic regular expressions that we did not cover. Called ...