shell_builtins(1) User Commands shell_builtins(1)
shell_builtins, case, for, foreach, function, if, repeat, select,
switch, until, while - shell command interpreter built-in commands
The shell command interpreters csh(1), ksh(1), and sh(1) have special
built-in commands. The commands case, for, foreach, function, if,
repeat, select, switch, until, and while are commands in the syntax
recognized by the shells. They are described in the Commands section of
the manual pages of the respective shells. The remaining commands
listed in the table below are built into the shells for reasons such as
efficiency or data sharing between command invocations. They are
described on their respective manual pages.
tab(); cw(2.750000i)| cw(2.750000i) lw(2.750000i)| lw(2.750000i). Com-
mandShell aliascsh, ksh bgcsh, ksh, sh breakcsh, ksh, sh casecsh, ksh,
sh cdcsh, ksh, sh chdircsh, sh continuecsh, ksh, sh dirscsh echocsh,
ksh, sh evalcsh, ksh, sh execcsh, ksh, sh exitcsh, ksh, sh exportksh,
sh fcksh fgcsh, ksh, sh forksh, sh foreachcsh functionksh getoptsksh,
sh globcsh gotocsh hashksh, sh hashstatcsh historycsh ifcsh, ksh, sh
jobscsh, ksh, sh killcsh, ksh, sh letksh limitcsh logincsh, ksh, sh
logoutcsh, ksh, sh nicecsh newgrpksh, sh nohupcsh notifycsh onintrcsh
popdcsh printksh pushdcsh pwdksh, sh readksh, sh readonlyksh, sh
rehashcsh repeatcsh returnksh, sh selectksh setcsh, ksh, sh setenvcsh
shiftcsh, ksh, sh sourcecsh stopcsh, ksh, sh suspendcsh, ksh, sh
switchcsh testksh, sh timecsh timesksh, sh trapksh, sh typeksh, sh
typesetksh ulimitksh, sh umaskcsh, ksh, sh unaliascsh, ksh unhashcsh
unlimitcsh unsetcsh, ksh, sh unsetenvcsh untilksh, sh waitcsh, ksh, sh
whenceksh whilecsh, ksh, sh
Bourne Shell, sh, Special Commands
Input/output redirection is now permitted for these commands. File
descriptor 1 is the default output location. When Job Control is
enabled, additional Special Commands are added to the shell's environ-
In addition to these built-in reserved command words, sh also uses:
: No effect; the command does nothing. A zero exit code
.filename Read and execute commands from filename and return. The
search path specified by PATH is used to find the
directory containing filename.
C shell, csh
Built-in commands are executed within the C shell. If a built-in com-
mand occurs as any component of a pipeline except the last, it is exe-
cuted in a subshell. In addition to these built-in reserved command
words, csh also uses:
: Null command. This command is interpreted, but performs
Korn Shell, ksh, Special Commands
Input/Output redirection is permitted. Unless otherwise indicated, the
output is written on file descriptor 1 and the exit status, when there
is no syntax error, is zero.
Commands that are preceded by one or two * (asterisks) are treated spe-
cially in the following ways:
1. Variable assignment lists preceding the command remain in effect
when the command completes.
2. I/O redirections are processed after variable assignments.
3. Errors cause a script that contains them to abort.
4. Words, following a command preceded by ** that are in the format of
a variable assignment, are expanded with the same rules as a vari-
able assignment. This means that tilde substitution is performed
after the = sign and word splitting and file name generation are
In addition to these built-in reserved command words, ksh also uses:
* : [ arg ... ] The command only expands parameters.
* .file [ arg ..Read the complete file then execute the commands. The
commands are executed in the current shell environment.
The search path specified by PATH is used to find the
directory containing file. If any arguments arg are
given, they become the positional parameters. Other-
wise, the positional parameters are unchanged. The exit
status is the exit status of the last command executed.
the loop termination test.
intro(1), alias(1), break(1), cd(1), chmod(1), csh(1), echo(1),
exec(1), exit(1), find(1), getoptcvt(1), getopts(1), glob(1), hash(1),
history(1), jobs(1), kill(1), ksh(1), let(1), limit(1), login(1),
logout(1), newgrp(1), nice(1), nohup(1), print(1), pwd(1), read(1),
readonly(1), set(1), sh(1), shift(1), suspend(1), test(1B), time(1),
times(1), trap(1), typeset(1), umask(1), wait(1), chdir(2), chmod(2),
creat(2), umask(2), getopt(3C), profile(4), environ(5)
SunOS 5.10 19 Aug 2003 shell_builtins(1)