Filters and pipes
If you're at all familiar with the Unix command line or, to a lesser extent, the Windows command line, then you'll have probably made use of pipes. A pipe, which is represented by the
| character is shorthand for "take the output of program A and put it into program B". This relatively simple idea makes the Unix command line incredibly powerful. For instance, if you wanted to list all the files in a directory and then sort them and filter for any which start with either the letters
g and end with an
f then the command might look like the following:
ls command lists all files and directories, the
sort command sorts them, and the
grep command matches file names against a regular expression. Running ...