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| = Builtin Commands = | = Bash Builtin Commands = The set of portable commands. |
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| == : == | == Commands == |
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| Does nothing; arguments passed to it are expanded but immediately discarded. | ||'''Command''' ||'''Description'''||'''Example'''|| ||`.` ||Alias for `source`|| || ||`:` ||No-op || || ||`alias` ||Creates an [[Bash/Alias|alias]]|| || ||`bind` || || || ||`builtin` ||Executes a builtin command|| || ||`caller` || || || ||`cd` ||Changes the current working directory|| || ||`command` ||Executes a command|| || ||`declare` ||Set a variable, optionally with a value|| || ||`dirs` || || || ||`disown` || || || ||`echo` || || || ||`enable` || || || ||`eval` ||Executes a command|| || ||`exec` ||Replaces the shell with a command|| || ||`exit` ||Causes a script or shell to exit immediately|| || ||`export` ||Marks one or more names as variables to be included in the environment of subsequently-called commands||`export varname="some value"`|| ||`fc` || || || ||`getopts` || || || ||`hash` || || || ||`help` ||Prints helpful information about a builtin command|| || ||`history` || || || ||`kill` || || || ||`let` || || || ||`local` ||Only valid within a function definition; see [[Bash/Function#Local_Scope|here]]|| || ||`logout` ||Exits a login shell immediately|| || ||`mapfile` || || || ||`popd` || || || ||`printf` || || || ||`pushd` || || || ||`pwd` ||Prints the current working directory|| || ||`read` || || || ||`readarray` || || || ||`readonly` || || || ||`set` ||Sets a [[Bash/ShellOptions|shell option]]|| || ||`shift` ||Renames the [[Bash/Variables#Positional_Variables|positional variables]]|| || ||`shopt` ||Sets a [[Bash/ShellOptions|shell option]]|| || ||`source` || || || ||`test` ||Executes a [[Bash/Test|test]]|| || ||`time` || || || ||`trap` ||Creates a [[Bash/Trap|here]]|| || ||`typeset` || || || ||`unalias` ||Removes an [[Bash/Alias|alias]]|| || ||`unset` ||Unsets a [[Bash/ShellOptions|shell option]]|| || ||`wait` || || || === Builtin === `builtin` can be useful to call a builtin command when there is a custom command with the same name. === Cd === Calling `cd` without an argument is the same as `cd ~`. `cd -` changes the current working directory to the previous working directory. === Command === `command` can be useful to call a command when there is a function with the same name. `command` is also commonly used to determine if a command is locally available. {{{ if ! command -v mypy >/dev/null 2>&1; then echo "cannot locate mypy; is it installed?" exit fi }}} === Declare === When used within a function definition, the variable is set to [[Bash/Function#Local_Scope|local scope]]. To create a variable that is marked for export, use: {{{ declare -x myvar }}} To create a variable that is marked for tracing, use: {{{ declare -t myvar }}} To create a read-only constant, use: {{{ declare -r myconst }}} To create an integer variable, use: {{{ declare -i myinteger }}} To create an [[Bash/Array|array]], use: {{{ declare -a myarray }}} To create an associative array, use: {{{ declare -A myarray }}} With some exceptions, these options can be combined. Additionally, options can be explicitly disabled by substituting the dash (`-`) with a plus sign (`+`). |
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| == Alias == | == Reserved Keywords == |
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| See [[Bash/Alias|here]]. | Some parts of the language are technically implemented as a command. |
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| ---- | See [[Bash/Looping|here]] for `break` and `continue`. See [[Bash/Function#Error_and_Return_Codes|here]] for `return`. See [[Bash/Completion|here]] for `compgen`, `complete, and `compopt`. See [[Bash/JobControl|here]] for `bg`, `coproc`, `fg`, and `jobs`. |
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| == Bg == |
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== Bind == ---- == Break == ---- == Builtin == ---- == Caller == ---- == Cd == ---- == Command == ---- == CompGen == ---- == Complete == ---- == CompOpt == ---- == Continue == ---- == Declare == ---- == Dirs == ---- == Disown == ---- == Echo == ---- == Enable == ---- == Eval == ---- == Exec == ---- == Exit == ---- == Export == ---- == Fc == ---- == Fg == ---- == GetOpts == ---- == Hash == ---- == Help == ---- == History == ---- == Jobs == ---- == Kill == ---- == Let == ---- == Local == ---- == LogOut == ---- == MapFile == ---- == PopD == ---- == PrintF == ---- == PushD == ---- == Pwd == ---- == Read == ---- == ReadArray == ---- == ReadOnly == ---- == Return == ---- == Set == See [[Bash/ShellOptions|here]]. ---- == Shift == ---- == ShOpt == See [[Bash/ShellOptions|here]]. ---- == Source == Aliased to `.`. ---- == Test == Aliased to `[`. See [[Bash/Test|here]]. ---- == Time == ---- == Trap == ---- == TypeSet == ---- == UnAlias == ---- == UnSet == ---- == Wait == |
CategoryRicottone |
Bash Builtin Commands
The set of portable commands.
Commands
Command |
Description |
Example |
. |
Alias for source |
|
: |
No-op |
|
alias |
Creates an alias |
|
bind |
|
|
builtin |
Executes a builtin command |
|
caller |
|
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cd |
Changes the current working directory |
|
command |
Executes a command |
|
declare |
Set a variable, optionally with a value |
|
dirs |
|
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disown |
|
|
echo |
|
|
enable |
|
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eval |
Executes a command |
|
exec |
Replaces the shell with a command |
|
exit |
Causes a script or shell to exit immediately |
|
export |
Marks one or more names as variables to be included in the environment of subsequently-called commands |
export varname="some value" |
fc |
|
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getopts |
|
|
hash |
|
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help |
Prints helpful information about a builtin command |
|
history |
|
|
kill |
|
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let |
|
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local |
Only valid within a function definition; see here |
|
logout |
Exits a login shell immediately |
|
mapfile |
|
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popd |
|
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printf |
|
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pushd |
|
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pwd |
Prints the current working directory |
|
read |
|
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readarray |
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readonly |
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set |
Sets a shell option |
|
shift |
Renames the positional variables |
|
shopt |
Sets a shell option |
|
source |
|
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test |
Executes a test |
|
time |
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trap |
Creates a here |
|
typeset |
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unalias |
Removes an alias |
|
unset |
Unsets a shell option |
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wait |
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Builtin
builtin can be useful to call a builtin command when there is a custom command with the same name.
Cd
Calling cd without an argument is the same as cd ~.
cd - changes the current working directory to the previous working directory.
Command
command can be useful to call a command when there is a function with the same name.
command is also commonly used to determine if a command is locally available.
if ! command -v mypy >/dev/null 2>&1; then echo "cannot locate mypy; is it installed?" exit fi
Declare
When used within a function definition, the variable is set to local scope.
To create a variable that is marked for export, use:
declare -x myvar
To create a variable that is marked for tracing, use:
declare -t myvar
To create a read-only constant, use:
declare -r myconst
To create an integer variable, use:
declare -i myinteger
To create an array, use:
declare -a myarray
To create an associative array, use:
declare -A myarray
With some exceptions, these options can be combined. Additionally, options can be explicitly disabled by substituting the dash (-) with a plus sign (+).
Reserved Keywords
Some parts of the language are technically implemented as a command.
See here for break and continue.
See here for return.
See here for compgen, complete, and compopt`.
See here for bg, coproc, fg, and jobs.