
shell - Bash regex =~ operator - Stack Overflow
Oct 18, 2013 · The [[ ]] is treated specially by bash; consider that an augmented version of [ ] construct: [ ] is actually a shell built-in command, which, can actually be implemented as an …
bash - What is the purpose of "&&" in a shell command? - Stack …
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 &&? (example)
arguments - What is $@ in Bash? - Stack Overflow
Oct 10, 2010 · Yes. Please see the man page of Bash (the first thing you go to) under Special Parameters:. Special Parameters. The shell treats several parameters specially.
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" …
Bash test: what does "=~" do? - Unix & Linux Stack Exchange
Jan 27, 2017 · help [[returns useful information—since [[an internal bash command—but does not say whether =~ uses basic or extended regex syntax. ⋯ The text you quoted is from the bash …
How do AND and OR operators work in Bash? - Stack Overflow
In bash, && and || have equal precendence and associate to the left. See Section 3.2.3 in the manual for details. So, your example is parsed as $ (echo this || echo that) && echo other And …
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 …
linux - What does $@ mean in a shell script? - Stack Overflow
Apr 3, 2012 · * Note: Word splitting. The shell splits tokens based on the contents of the IFS environment variable. Its default value is \t\n; i.e., whitespace, tab, and newline.
Meaning of $? (dollar question mark) in shell scripts
Aug 1, 2019 · In Bash, when you hit enter, a fork + exec + wait happens like above, and bash then sets $? to the exit status of the forked process. Note: for built-in commands like echo, a …
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.