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 …
What's the difference between <<, <<< and < < in bash?
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 …
arguments - What is $@ in Bash? - Stack Overflow
Oct 10, 2010 · I reckon that the handle $@ in a shell script is an array of all arguments given to the script. Is this true? I ask because I normally use search engines to gather information, but I …
bash - Shell equality operators (=, ==, -eq) - Stack Overflow
It depends on the Test Construct around the operator. Your options are double parentheses, double brackets, single brackets, or test. If you use ((…)), you are testing arithmetic equality …
What do the -n and -a options do in a bash if statement?
The switches -a and -n are not strictly part of a bash if statement in that the if command does not process these switches. What are primaries? I call them "switches", but the bash …
An "and" operator for an "if" statement in Bash - Stack Overflow
An "and" operator for an "if" statement in Bash Asked 12 years, 11 months ago Modified 1 year, 3 months ago Viewed 987k times
Find all files containing a specific text (string) on Linux
Jun 6, 2013 · How do I find all files containing a specific string of text within their file contents? The following doesn't work. It seems to display every single file in the system. find / -type f …
What is the difference between the Bash operators [[ vs [ vs ( vs
Aug 28, 2016 · Some differences on Bash 4.3.11: POSIX vs Bash extension: [ is POSIX [[ is a Bash extension inspired from Korn shell regular command vs magic [ is just a regular …
An example of how to use getopts in bash - Stack Overflow
May 10, 2013 · I want to call myscript file in this way: $ ./myscript -s 45 -p any_string or $ ./myscript -h #should display help $ ./myscript #should display help My requirements are: …
How to compare strings in Bash - Stack Overflow
Feb 10, 2010 · How do I compare a variable to a string (and do something if they match)?