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 external …

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 …

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 …

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.

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" …

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.

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 …

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 …

your understanding is right. For detailed info on {} see bash ref - parameter expansion 'for' and 'while' have different syntax and offer different styles of programmer control for an iteration. …

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 …