Sep 14, 2012 · In Bash, there appear to be several variables which hold special, consistently-meaning values. For instance, ./myprogram &; echo $! will return the PID of the process which …

How do AND and OR operators work in Bash? Asked 13 years ago Modified 2 years, 9 months ago Viewed 22k times

By default, Bash does not do this. This default behavior is exactly what you want if you are using Bash on the command line you don't want a typo to log you out! But in a script, you really want the …

Dec 22, 2010 · In shell, when you see $ command one && command two the intent is to execute the command that follows the only if the first command is successful. This is idiomatic of Posix shells, …

Jul 25, 2017 · Furthermore, when you use bash -c, behavior is different than if you run an executable shell script, because in the latter case the argument with index 0 is the shell command used to invoke it.

If not quoted, it is a pattern match! (From the Bash man page: "Any part of the pattern may be quoted to force it to be matched as a string."). Here in Bash, the two statements yielding "yes" are pattern …

Oct 18, 2013 · What is the operator =~ called? I'm not sure it has a name. The bash documentation just calls it the =~ operator. Is it only used to compare the right side against the left side? The right side is …

Aug 1, 2019 · What does echo $? mean in shell programming? true echo $? # echoes 0 false echo $? # echoes 1 From the manual: (acessible by calling man bash in your shell) ? Expands to the exit status …

Sep 27, 2015 · What's the difference between <<, <<< and < < in bash? Here document << is known as here-document structure. You let the program know what will be the ending text, and whenever that …

All the bash command line switches are documented in man bash. -e Exit immediately if a pipeline (which may consist of a single simple command), a subshell command enclosed in parentheses, or …