
linux - What does $@ mean in a shell script? - Stack Overflow
Apr 3, 2012 · The shell splits tokens based on the contents of the IFS environment variable. Its default value is \t\n; i.e., whitespace, tab, and newline. Expanding "$@" gives you a pristine …
regex - Meaning of "=~" operator in shell script - Stack Overflow
Sep 17, 2012 · The return value is 0 if the string matches the pattern, and 1 otherwise. If the regular expression is syntactically incorrect, the conditional expression's return value is 2. If …
What is the $? (dollar question mark) variable in shell scripting?
The shell treats several parameters specially. These parameters may only be referenced; assignment to them is not allowed. [...]? Expands to the exit status of the most recently …
What does $# mean in shell? - Unix & Linux Stack Exchange
You can always check the man page of your shell. man bash says: Special Parameters # Expands to the number of positional parameters in decimal. Therefore a shell script can check …
Difference between $ {} and $ () in a shell script - Super User
The above (along with many more forms of ${parameter…something_else} constructs) are discussed at greater length in the shell’s man page, bash(1). A Note on Quotes. Note that you …
What is the meaning of $? in a shell script? - linux
Feb 20, 2011 · This latter usage is faster, does not contaminate the shell's variable namespace with what amounts to temp variables, can often be a lot more readable for humans and …
bash - Shell equality operators (=, ==, -eq) - Stack Overflow
What is the difference between =, == and -eq in shell scripting? Is there any difference between the following?
shell - What is the "eval" command in bash? - Unix & Linux Stack …
In shell terminology, eval is a built-in, not a function. In practice, built-ins behave a lot like functions that don't have an in-language definition, but not quite (as becomes apparent if you …
shell - What does "--" (double dash / double hyphen) mean?
In man bash we can read in Shell Builtin Commands section : Unless otherwise noted, each builtin command documented in this section as accepting options preceded by -accepts --to …
shell - Difference between sh and Bash - Stack Overflow
Shell - "Shell" is a program, which facilitates the interaction between the user and the operating system (kernel). There are many shell implementations available, like sh, Bash, C shell, Z …