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sh(1) [hpux man page]

sh(1)							      General Commands Manual							     sh(1)

NAME
sh - overview of various system shells SYNOPSIS
POSIX Shell option] ... string] [arg ...] option] ... string] [arg ...] Korn Shell option] ... string] [arg ...] option] ... string] [arg ...] C Shell [command_file] [argument_list ...] Key Shell DESCRIPTION
Remarks The POSIX .2 standard requires that, on a POSIX-compliant system, executing the command activates the POSIX shell (located in file on HP-UX systems), and executing the command produces an on-line manual entry that displays the syntax of the POSIX shell command-line. However, the command has historically been associated with the conventional Bourne shell, which could confuse some users. To meet stan- dards requirements and also clarify the relationships of the various shells and where they reside on the system, this entry provides com- mand-line syntax and a brief description of each shell, and lists the names of the manual entries where each shell is described in greater detail. The Bourne shell is removed from the system starting with HP-UX 11i Version 1.5. Please use the POSIX shell as an alternative. Shell Descriptions The HP-UX operating system supports the following shells: POSIX-conforming command programming language and command interpreter residing in file Can execute commands read from a terminal or a file. This shell conforms to current POSIX standards in effect at the time the HP-UX system release was introduced, and is similar to the Korn shell in many respects. Similar in many respects to the Korn shell, the POSIX shell contains a history mechanism, supports job control, and provides various other useful features. Korn-shell command programming language and commands interpreter residing in file Can execute commands read from a terminal or a file. This shell, like the POSIX shell, contains a his- tory mechanism, supports job control, and provides various other useful features. A command language interpreter that incorporates a command history buffer, C-language-like syntax, and job control facilities. Restricted version of the POSIX shell command interpreter. Sets up a login name and execution environment whose capabilities are more controlled (restricted) than normal user shells. restricted version of the Korn-shell command interpreter Sets up a login name and execution environment whose capabilities are more controlled (restricted) than normal user shells. An extension of the standard Korn Shell that uses hierarchical softkey menus and context-sensitive help. +--------------+--------------------+ | To obtain: | Use the command: | +--------------+--------------------+ | POSIX Shell | /usr/bin/sh ... | | Korn Shell | /usr/bin/ksh ... | | C Shell | /usr/bin/csh ... | | Key Shell | /usr/bin/keysh | +--------------+--------------------+ These shells can also be the default invocation, depending on the entry in the file. See also chsh(1). WARNINGS
Many manual entries contain descriptions of shell behavior or describe program or application behavior similar to ``the shell'' with a ref- erence to ``see sh(1)''. SEE ALSO
For more information on the various individual shells, see: keysh(1) Key Shell description. ksh(1) Korn Shell description. sh-posix(1) POSIX Shell description. csh(1) C Shell description. sh(1)

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shell_builtins(1)														 shell_builtins(1)

NAME
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. | Command | Shell alias |csh, ksh bg |csh, ksh, sh break |csh, ksh, sh case |csh, ksh, sh cd |csh, ksh, sh chdir |csh, sh continue |csh, ksh, sh dirs |csh echo |csh, ksh, sh eval |csh, ksh, sh exec |csh, ksh, sh exit |csh, ksh, sh export |ksh, sh false |ksh fc |ksh fg |csh, ksh, sh for |ksh, sh foreach |csh function |ksh getopts |ksh, sh glob |csh goto |csh hash |ksh, sh hashstat |csh history |csh if |csh, ksh, sh jobs |csh, ksh, sh kill |csh, ksh, sh let |ksh limit |csh login |csh, ksh, sh logout |csh, ksh, sh nice |csh newgrp |ksh, sh nohup |csh notify |csh onintr |csh popd |csh print |ksh pushd |csh pwd |ksh, sh read |ksh, sh readonly |ksh, sh rehash |csh repeat |csh return |ksh, sh select |ksh set |csh, ksh, sh setenv |csh shift |csh, ksh, sh source |csh stop |csh, ksh, sh suspend |csh, ksh, sh switch |csh test |ksh, sh time |csh times |ksh, sh trap |ksh, sh true |ksh type |ksh, sh typeset |ksh ulimit |ksh, sh umask |csh, ksh, sh unalias |csh, ksh unhash |csh unlimit |csh unset |csh, ksh, sh unsetenv |csh until |ksh, sh wait |csh, ksh, sh whence |ksh while |csh, 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 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 con- taining 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 vari- able assignment. This means that tilde substitution is performed after the = sign and word splitting and file name generation 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 given, they become the posi- tional parameters. Otherwise, the positional parameters are unchanged. The exit status is the exit status of the last com- mand 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), his- tory(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), read- only(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) 29 Jun 2005 shell_builtins(1)

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