What Are the Special Dollar Sign Shell Variables? - Baeldung
Jul 6, 2024 · What Are the Special Dollar Sign Shell Variables? 1. Overview. The dollar sign ($) plays a crucial role in shell scripting. This ranges from argument handling to process management, and even …
15 Special Characters You Need to Know for Bash
Oct 3, 2025 · If you want to master the Bash shell on Linux, macOS, or another UNIX-like system, special characters (like ~, *, |, and >) are critical. We'll help you unravel these cryptic Linux command …
What Does $ Mean in Bash/Makefile? Understanding Double Dollar …
Dec 4, 2025 · In Makefiles, $$ serves a completely different purpose: escaping the dollar sign ($) so it’s passed to the shell when executing recipe commands. Makefile recipes (the commands under a …
What is Linux? - Linux.com
Looking to get started in Linux? Develop a good working knowledge of Linux using both the graphical interface and command line across the major Linux distribution families with The Linux Foundation’s …
What is $* and $# in Linux? - Super User
on the command line, individually quoted ("$1" "$2" ...). So basically, $# is a number of arguments given when your script was executed. $* is a string containing all arguments. For example, $1 is the first …
What is the $? (dollar question mark) variable in shell scripting?
To understand $?, you must first understand the concept of process exit status which is defined by POSIX. In Linux: when a process calls the exit system call, the kernel stores the value passed to the …
Linux - Wikipedia
Linux distributions are frequently used in server platforms. [27][28] Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses and recommends the name " …
Unix / Linux - Special Variables - Online Tutorials Library
There are special parameters that allow accessing all the command-line arguments at once. $* and $@ both will act the same unless they are enclosed in double quotes, "". Both the parameters specify the …
Special Variables in Bash Shell [With Script Examples] - Linux Handbook
Apr 4, 2023 · Gets the status of the last command or the most recently executed process. $! Shows the process ID of the last background command. Gets the process ID of the current shell. It will print the …
What are $0, $#, $*, $@, $?, $$ etc. in Linux Bash/Shell script, What ...
Dec 22, 2020 · That is, "$*" is equivalent to "$1c$2c…", where c is the first character of the value of the IFS variable. If IFS is unset, the parameters are separated by spaces. If IFS is null, the parameters …