March 2002
Beginner
504 pages
10h 47m
English
Content preview from Sams Teach Yourself Shell Programming in 24 Hours, Second Edition
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Command and Arithmetic Substitution
Two additional forms of substitution are command and arithmetic substitution. Command substitution enables you to capture the output of a command, whereas arithmetic substitution enables you to perform basic integer math using the shell.
Command Substitution
Command substitution is the mechanism by which the shell performs a given set of commands and then substitutes their output in the place of the commands. Command substitution is performed when a command is given as
`command`
Here command can be a simple command, a pipeline, or a list.
 | Make sure that you are using the backquote character , not the single ... |
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.