shell_builtins(1)						   User Commands						 shell_builtins(1)

NAME

       shell_builtins, case, for, foreach, function, if, repeat, select, switch, until, while - shell command interpreter built-in commands

DESCRIPTION

       The  shell  command interpreters csh(1), ksh(1), ksh93(1), and sh(1) have special built-in commands. The commands case, for, foreach, func-
       tion, 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. In ksh93(1), fc, hash, stop, suspend, times, and type are aliases by default. In
       ksh93, the following built-ins are bound to the /bin pathname by default and are invoked if the pathname search	encounters  an	executable
       command of that name in the /bin or /usr/bin directory: cat, chown, getconf, head, mkdir, rmdir, tee, uniq, and wc.

       The  remaining commands listed in the following table are built into the shells for reasons such as efficiency or data sharing between com-
       mand invocations. They are described on their respective manual pages.

		 Command			Shell
       -----------------------------------------------------------
       ++**alias		     csh, ksh, ksh93
       bg			     csh, ksh, ksh93, sh
       +*break			     csh, ksh, ksh93, sh
       builtin			     ksh93
       case			     csh, ksh, ksh93, sh
       cat			     ksh93
       cd			     csh, ksh, ksh93, sh
       chdir			     csh, sh
       chown			     ksh93
       command			     ksh93
       +*continue		     csh, ksh, ksh93, sh
       dirs			     csh
       disown			     ksh93
       echo			     csh, ksh, ksh93, sh
       +*eval			     csh, ksh, ksh93, sh
       +*exec			     csh, ksh, ksh93, sh
       +*exit			     csh, ksh, ksh93, sh
       ++**export		     ksh, ksh93, sh
       false			     ksh, ksh93
       fc			     ksh, ksh93
       fg			     csh, ksh, ksh93, sh
       for			     ksh, ksh93, sh
       foreach			     csh
       function 		     ksh, ksh93
       getconf			     ksh93
       getopts			     ksh, ksh93, sh
       glob			     csh
       goto			     csh
       hash			     ksh, ksh93, sh
       hashstat 		     csh
       head			     ksh93
       hist			     ksh93
       history			     csh
       if			     csh, ksh, ksh93, sh
       jobs			     csh, ksh, ksh93, sh
       kill			     csh, ksh, ksh93, sh
       let			     ksh, ksh93,
       limit			     csh
       login			     csh, ksh, ksh93, sh
       logout			     csh
       mkdir			     ksh93
       nice			     csh

       +*newgrp 		     ksh, ksh93, sh
       nohup			     csh
       notify			     csh
       onintr			     csh
       popd			     csh
       print			     ksh, ksh93
       printf			     ksh93
       pushd			     csh
       pwd			     ksh, ksh93, sh
       read			     ksh, ksh93, sh
       ++**readonly		     ksh, ksh93, sh
       rehash			     csh
       repeat			     csh
       +*return 		     ksh, ksh93, sh
       select			     ksh, ksh93
       +set			     csh, ksh, ksh93, sh
       setenv			     csh
       shift			     csh, ksh, ksh93, sh
       sleep			     ksh93
       source			     csh
       stop			     csh, ksh, ksh93, sh
       suspend			     csh, ksh, sh
       switch			     csh
       tee			     ksh93
       test			     ksh, ksh93, sh
       time			     csh
       *times			     ksh, ksh93, sh
       *+trap			     ksh, ksh93, sh
       true			     ksh, ksh93
       type			     ksh, ksh93, sh
       ++**typeset		     ksh, ksh93
       ulimit			     ksh, ksh93, sh
       umask			     csh, ksh, ksh93, sh
       +unalias 		     csh, ksh, ksh93
       unhash			     csh
       uniq			     ksh93
       unlimit			     csh
       +unset			     csh, ksh, ksh93, sh
       unsetenv 		     csh
       until			     ksh, ksh93, sh
       *wait			     csh, ksh, ksh93, sh
       whence			     ksh, ksh93
       while			     csh, ksh, ksh93, 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 environment.

       In addition to these built-in reserved command words, sh also uses:

       :	      No effect; the command does nothing. A zero exit code is returned.

       .filename      Read and execute commands from filename and return. The search path specified by PATH is used to find the directory contain-
		      ing filename.

   C shell, csh
       Built-in commands are executed within the C shell. If a built-in command 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 no action.

   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 specially 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
		  variable  assignment.  This means that tilde substitution is performed after the = sign and word splitting and file name genera-
		  tion are not performed.

       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
				    specified, they become the positional parameters. Otherwise, the positional parameters are unchanged. The exit
				    status is the exit status of the last command executed. the loop termination test.

   Korn Shell, ksh93, 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.

       Except for :, true, false, echo, newgrp, and login, all built-in commands accept -- to indicate end of options.	They  also  interpret  the
       option  --man as a request to display the manual page onto standard error and -? as a help request which prints a usage message on standard
       error.

       Commands that are preceded by one or two + are treated specially 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.	  They are not valid function names.

	   5.	  Words, following a command preceded by ++ that are in the format of a variable assignment, are expanded with the same rules as a
		  variable  assignment. This means that tilde substitution is performed after the = sign and field splitting and file name genera-
		  tion are not performed.

       In addition to these built-in reserved command words, ksh93 also uses:

       : [ arg ... ]		  The command only expands parameters.

       .name [ arg ... ]	  If name is a function defined with the function name reserved word syntax, the function is executed in the  cur-
				  rent	environment  (as  if  it had been defined with the name() syntax.) Otherwise if name refers to a file, the
				  file is read in its entirety and the commands are executed in the current shell  environment.  The  search  path
				  specified  by  PATH  is used to find the directory containing the file. If any arguments arg are specified, they
				  become the positional parameters while processing the . command  and	the  original  positional  parameters  are
				  restored  upon completion. Otherwise the positional parameters are unchanged. The exit status is the exit status
				  of the last command executed.

SEE ALSO

       Intro(1), alias(1), break(1), builtin(1), cd(1), chmod(1), csh(1), disown(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), ksh93(1), let(1), limit(1), login(1), logout(1), newgrp(1), nice(1), nohup(1),
       print(1), printf(1), pwd(1), read(1), readonly(1), set(1),  sh(1),  shift(1),  sleep(1),  suspend(1),  test(1)test(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 5.11							    20 Nov 2007 						 shell_builtins(1)