Search results
Results from the WOW.Com Content Network
In Unix shells, variables may be assigned without the export keyword. Variables defined in this way are displayed by the set command, but are not true environment variables, as they are stored only by the shell and are unknown to all other processes.
export variable: export var set --export var Options discoverable via tab completion function-local variable: local var by default scope-local variable: no equivalent set --local var remove variable: unset var set --erase var check if a variable exists: test -v var set --query var array initialization: var=( a b c )
env is a shell command for Unix and Unix-like operating systems. It is used to either print a list of environment variables or run another utility in an altered environment without having to modify the currently existing environment. Using env, variables may be added or removed, and existing variables may be changed by assigning new values to them.
While Bash was developed for UNIX and UNIX-like operating systems, such as GNU/Linux, [18] it is also available on Android, macOS, Windows, and numerous other current and historical operating systems. "Although there have been attempts to create specialized shells, the Bourne shell derivatives continue to be the primary shells in use."
TMPDIR is the canonical environment variable in Unix and POSIX [1] that should be used to specify a temporary directory for scratch space.Most Unix programs will honor this setting and use its value to denote the scratch area for temporary files instead of the common default of /tmp [2] [3] or /var/tmp.
Environment variables are a facility provided by some operating systems.Within the OS's shell (ksh in Unix, bash in Linux, COMMAND.COM in DOS and CMD.EXE in Windows) they are a kind of variable: for instance, in unix and related systems an ordinary variable becomes an environment variable when the export keyword is used.
The Z shell (Zsh) is a Unix shell that can be used as an interactive login shell and as a command interpreter for shell scripting. Zsh is an extended Bourne shell with many improvements, including some features of Bash, ksh, and tcsh. Zsh was created by Paul Falstad in 1990 while he was a student at Princeton University.
fc is a builtin command in the Bash and Zsh shells and is an initialism for "fix command". It is particularly helpful for editing complex, multi-line commands. The editor can be specified by setting the EDITOR (changes the default editor) or the FCEDIT environment variable.