NAME
sh — overview of various system shells
SYNOPSIS
POSIX Shell:
sh
[±aefhikmnoprstuvx]
[±o
option] ...
[-c
string]
[arg ...]
rsh
[±aefhikmnoprstuvx]
[±o
option] ...
[-c
string]
[arg ...]
Bourne Shell:
sh
[--acefhiknrstuvx ...]
[arg ...]
rsh
[--acefhiknrstuvx ...]
[arg ...]
Korn Shell:
ksh
[±aefhikmnoprstuvx]
[±o
option] ...
[-c
string]
[arg ...]
rksh
[±aefhikmnoprstuvx]
[±o
option] ...
[-c
string]
[arg ...]
C Shell:
csh
[-cefinstvxTVX]
[command_file]
[argument_list ...]
DESCRIPTION
Remarks:
The
POSIX.2 standard requires that, on a
POSIX-compliant system, executing the command
sh
activates the
POSIX
shell (located in file
/usr/bin/sh
on
HP-UX
systems), and executing the command
man sh
produces an on-line manual entry that displays the syntax of the
POSIX
shell command-line.
However, the
sh
command has historically been associated
with the conventional Bourne shell,
which could confuse some users.
To meet standards requirements
and also clarify the relationships of the various shells
and where they reside on the system,
this entry provides command-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.
Shell Descriptions
The
HP-UX
operating system supports the following shells:
- sh
POSIX-conforming command programming language and command interpreter
residing in file
/usr/bin/sh.
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.
- sh
Bourne-shell command programming language and commands interpreter
residing in file
/usr/old/bin/sh.
Can execute commands read from a terminal or a file.
This shell lacks many features contained in the
POSIX
and Korn shells. The Bourne shell will be obsoleted. Users are
strongly encouraged to switch to the POSIX shell. The Bourne shell
will still be available as
/usr/old/bin/sh,
for those users have to use it.
- ksh
Korn-shell command programming language and commands interpreter
residing in file
/usr/bin/ksh.
Can execute commands read from a terminal or a file.
This shell, like the
POSIX
shell, contains a history mechanism, supports job control,
and provides various other useful features.
- csh
A command language interpreter
that incorporates a command history buffer,
C-language-like syntax, and job control facilities.
- rsh
Restricted version of the POSIX or Bourne shell command interpreter.
Sets up a login name and execution environment
whose capabilities are more controlled (restricted)
than normal user shells.
- rksh
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.
- keysh
An extension of the standard Korn Shell
that uses hierarchical softkey menus and context-sensitive help.
These shells can also be the default invocation,
depending on the entry in the
/etc/passwd
file.
See also
chsh(1).
Whether the
sh
command invokes the Bourne Shell or the
POSIX
Shell depends on the setting of the
PATH
environment variable.
The default
PATH
in file
/etc/profile
is set to invoke the
POSIX
shell.
WARNINGS
Many manual entries contain descriptions of shell behavior
or describe program or application behavior similar to ``the shell''
with a reference to ``see
sh(1)''.
SEE ALSO
For more information on the various individual shells, see:
- sh-bourne(1)
Bourne Shell
(/usr/old/bin/sh)
description.
- ksh(1)
Korn Shell
(/usr/bin/ksh)
description.
- sh-posix(1)
POSIX
Shell
(/usr/bin/sh)
description.
- csh(1)
C Shell
(/usr/bin/csh)
description.
- keysh(1)
Key Shell
(/usr/bin/keysh)
description.
