bash - What are the special dollar sign shell variables ... - Stack ...
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 …
bash - What is the purpose of "&&" in a shell command? - Stack …
Oct 27, 2021 · As far as I know, using & after the command is for running it in the background. Example of & usage: tar -czf file.tar.gz dirname & But how about …
linux - What does $@ mean in a shell script? - Stack Overflow
Apr 3, 2012 · (View Special parameters - Bash Manual) For instance, if you call ./someScript.sh foo bar then $@ will be equal to foo bar. If you do:./someScript.sh foo bar and then inside …
bash - Shell equality operators (=, ==, -eq) - Stack Overflow
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" …
An "and" operator for an "if" statement in Bash - Stack Overflow
Modern shells such as Bash and Zsh have inherited this construct from Ksh, but it is not part of the POSIX specification. If you're in an environment where you have to be strictly POSIX …
What's the difference between <<, <<< and < < in bash?
Sep 27, 2015 · In bash these are implemented via temp files, usually in the form /tmp/sh-thd.<random string>, while in dash they are implemented as anonymous pipes. This can be …
How to compare strings in Bash - Stack Overflow
Feb 10, 2010 · Bash always seemed backward with numeric evaluations using an operator consisting of a string (-eq) and string comparisons using a numeric operator "==" or "=" just …
bash - Difference between 'if -e' and 'if -f' - Stack Overflow
Apr 18, 2012 · $ man bash -e file True if file exists. -f file True if file exists and is a regular file. A regular file is something that isn't a directory, symlink, socket, device, etc.
Which characters need to be escaped when using Bash?
I noticed that Bash automatically escapes some characters when using auto-complete. For example, if you have a directory named dir:A, Bash will auto-complete to dir\:A. Using this, I …
How do I iterate over a range of numbers defined by variables in …
Oct 4, 2008 · Bash is a great shell and I use it interactively, but I don't put bash-isms into my scripts. Scripts might need a faster shell, a more secure one, a more embedded-style one. …