sh-bourne(1)

NAME

sh, rsh — Bourne shell, the standard/restricted command programming language

SYNOPSIS

sh [--acefhiknrstuvx ...] [arg ...]

rsh [--acefhiknrstuvx ...] [arg ...]

DESCRIPTION

sh is a command programming language that executes commands read from a terminal or a file. rsh is a restricted version of the standard command interpreter sh; it is used to set up login names and execution environments whose capabilities are more controlled than those of the standard shell. See ``Invocation'' and ``Special Commands'' sections later in this entry for details about command line options and arguments, particularly the set command.

Definitions

A blank is a tab or a space character. A name is a sequence of letters, digits, or underscores beginning with a letter or underscore. A parameter is a name, a digit, or any of the characters *, @, #, ?, -, $, and !.

Commands

A simple-command is a sequence of non-blank words separated by blanks. The first word specifies the name of the command to be executed. Except as specified below, the remaining words are passed as arguments to the invoked command. The command name is passed as argument 0 (see exec(2)). The value of a simple-command is its exit status if it terminates normally, or (octal) 200+status if it terminates abnormally (see signal(5) for a list of status values).

A pipeline is a sequence of one or more commands separated by | (or, for historical compatibility, by ^). The standard output of each command except the last is connected by a pipe(2) to the standard input of the next command. Each command is run as a separate process and the shell waits for the last command to terminate. The exit status of a pipeline is the exit status of the last command.

A list is a sequence of one or more pipelines separated by ;, &, &&, or ||, and optionally terminated by ; or &. Of these four symbols, ; and & have equal precedence, which is lower than that of && and ||. The symbols && and || also have equal precedence. A semicolon (;) causes sequential execution of the preceding pipeline; an ampersand (&) causes asynchronous execution of the preceding pipeline (i.e., the shell does not wait for that pipeline to finish). The symbol && (||) causes the list following it to be executed only if the preceding pipeline returns a zero (non-zero) exit status. An arbitrary number of new-line characters instead of semicolons can appear in a list to delimit commands.

A command is either a simple-command or one of the following. Unless otherwise stated, the value returned by a command is that of the last simple-command executed in the command.

for name [ in word ... ] do list done

Each time a for command is executed, name is set to the next word taken from the in word list. If in word ... is omitted, the for command executes the do list once for each positional parameter that is set (see Parameter Substitution below). Execution ends when there are no more words in the list.

case word in [pattern [| pattern] ... ) list ;;] ... esac

A case command executes the list associated with the first pattern that matches word. The form of the patterns is the Pattern Matching Notation as qualified for the case command (see regexp(5)).

if list then list [elif list then list] ... [else list] fi

The list following if is executed and, if it returns a zero exit status, the list following the first then is executed. Otherwise, the list following elif is executed and, if its value is zero, the list following the next then is executed. Failing that, the else list is executed. If no else list or then list is executed, the if command returns a zero exit status.

while list do list done

A while command repeatedly executes the while list and, if the exit status of the last command in the list is zero, executes the do list; otherwise the loop terminates. If no commands in the do list are executed, the while command returns a zero exit status; until can be used in place of while to negate the loop termination test.

(list)

Execute list in a sub-shell.

{list;}

The purpose of using braces is to allow the aggregate output from list to be redirected elsewhere. If redirection is used as in:

{list;} >file

a subshell is created to execute list. This implies that any shell variables set, created, or modified within the {} do not retain their values outside the {}. If no redirection is used, a subshell is not created, and shell modifications made within the {} are preserved.

name () {list;}

Define a function which is referenced by name. The body of the function is the list of commands between { and }. Execution of functions is described below (see ``Execution'').

The following words are recognized only as the first word of a command, and when not quoted:

if then else elif fi case esac for while until do done { } 

Comments

A word beginning with # causes that word and all the following characters up to a new-line character to be ignored.

Command Substitution

The standard output from a command enclosed in a pair of grave accents (``) can be used as part or all of a word; trailing new-lines are removed.

Parameter Substitution

The $ character is used to introduce substitutable parameters. There are two types of parameters, positional and keyword. If parameter is a digit, it is a positional parameter. Positional parameters can be assigned values by set. Keyword parameters (also known as variables) can be assigned values by writing:

name=value[name=value]...

Pattern-matching is not performed on value. Having a function and a variable with the same name is not allowed.

${parameter}: The value, if any, of the parameter is substituted. Braces are required only when parameter is followed by a letter, digit, or underscore that is not to be interpreted as part of its name. If parameter is * or @, all positional parameters, starting with $1, are substituted (separated by spaces). Parameter $0 is set from argument zero when the shell is invoked.
${parameter:-word}: If parameter is set and is non-null, substitute its value; otherwise substitute word.
${parameter:=word}: If parameter is not set or is null, set it to word; the value of the parameter is then substituted. Positional parameters cannot be assigned to in this way.
${parameter:?word}: If parameter is set and is non-null, substitute its value; otherwise, print word and exit from the shell. If word is omitted, the message ``parameter null or not set'' is printed.
${parameter:+word}: If parameter is set and is non-null, substitute word; otherwise substitute nothing.

In the above, word is not evaluated unless it is to be used as the substituted string. Thus, in the following example, pwd is executed only if d is not set or is null:

echo ${d:-`pwd`} 

If the colon (:) is omitted from the above expressions, the shell only checks whether parameter is set or not.

The following parameters are automatically set by the shell:

#: The number of positional parameters in decimal.
-: Flags supplied to the shell on invocation or by the set command.
?: The decimal value returned by the last synchronously executed command.
$: The process id of the last separately-invoked shell (i.e., a shell arising from direct invocation or #!). This parameter is not updated for subshells arising from (), command substitution, etc.
!: The process number of the last background command invoked.
LINES
COLUMNS: The number of lines and columns in the current display area. These parameters are set only under specific circumstances. See Signals.

The following parameters are used by the shell:

HOME: The default argument (home directory) for the cd command.
PATH: The search path for commands (see ``Execution'' below). Users executing under rsh cannot change PATH.
CDPATH: The search path for the cd command.
MAIL: If this parameter is set to the name of a mail file and the MAILPATH parameter is not set, the shell informs the user of the arrival of mail in the specified file.
MAILCHECK: This parameter specifies how often (in seconds) the shell will check for the arrival of mail in the files specified by the MAILPATH or MAIL parameters. The default value is 600 seconds (10 minutes). If set to 0, the shell checks before each prompt.
MAILPATH: A colon (:)-separated list of file names. If this parameter is set, the shell informs the user of the arrival of mail in any of the specified files. Each file name can be followed by % and a message to be printed when the modification time changes. The default message is you have mail.
PS1: Primary prompt string, by default ``$ ''.
PS2: Secondary prompt string, by default ``> ''.
IFS: Internal field separators, normally space, tab, and new-line.
SHACCT: If this parameter is set to the name of a file writable by the user, the shell writes an accounting record in the file for each shell procedure executed. Accounting routines such as acctcom(1M) and acctcms(1M) can be used to analyze the data collected.
SHELL: When the shell is invoked, it scans the environment (see ``Environment'' below) for this name. If it is found and there is an r in the file name part of its value, the shell becomes a restricted shell. SHELL is also used by some processors to determine which command interpreter to run.

The shell gives default values to PATH, PS1, PS2, MAILCHECK, and IFS. HOME and MAIL are set by login(1).

Blank Interpretation

After parameter and command substitution, the results of substitution are scanned for internal field separator characters (those found in IFS) and split into distinct arguments where such characters are found. Explicit null arguments ("" or \'\') are retained. Implicit null arguments (those resulting from parameters that have no values) are removed.

File Name Generation

Following substitution, each command word is processed as a pattern for file name expansion. The form of the patterns is the Pattern Matching Notation defined by regexp(5).

Quoting

The following characters have a special meaning to the shell and cause termination of a word unless quoted:

;, &, (, ), |, ^, <, >, new-line, space, tab, # (comment)

A character can be quoted (i.e., made to stand for itself) by preceding it with a \. The pair \new-line is ignored. All characters enclosed between a pair of single quote marks (\'\'), except a single quote, are quoted. Inside double quote marks (""), parameter and command substitution occurs and \ quotes the characters \, `, ", and $. "$*" is equivalent to "$1 $2 ...", whereas "$@" is equivalent to "$1""$2" ....

Prompting

When used interactively, the shell prompts with the value of PS1 before reading a command. If at any time a new-line is typed and further input is needed to complete a command, the secondary prompt (i.e., the value of PS2) is issued.

Input/Output

Before a command is executed, its input and output can be redirected using a special notation interpreted by the shell. The following can appear anywhere in a simple-command or can precede or follow a command and are not passed on to the invoked command; substitution occurs before word or digit is used:

<word: Use file word as standard input (file descriptor 0).
>word: Use file word as standard output (file descriptor 1). If the file does not exist then it is created; otherwise, it is truncated to zero length.
>>word: Use file word as standard output. If the file exists then output is appended to it (by first seeking to the end-of-file); otherwise, the file is created.
<<[-]word: The shell input is read up to a line that is the same as word, or to an end-of-file. The resulting document becomes the standard input. If any character of word is quoted, no interpretation is placed upon the characters of the document; otherwise, parameter and command substitution occurs, (unescaped) \new-line is ignored, and \ must be used to quote the characters \, $, `, and the first character of word. If - is appended to <<, all leading tabs are stripped from word and from the document.
<&digit: Use the file associated with file descriptor digit as standard input. Similarly for the standard output using >&digit (see dup(2)). Note that digit must be in the range 0 through 9.
<&-: The standard input is closed. Similarly for the standard output using >&-.

If any of the above is preceded by a digit in the range 0 through 9, the file descriptor that becomes associated with the file is that specified by the digit (rather than the default 0 or 1). For example:

... 2>&1

associates file descriptor 2 with the file currently associated with file descriptor 1. Note that this type of I/O redirection is necessary when synchronously collecting standard output and standard error output in the same file. Redirecting standard output and standard error separately causes asynchronous collection of data at the destination (information written to standard output can be subsequently over-written by information written to standard error and vice-versa).

The order in which redirections are specified is significant. The shell evaluates redirections left-to-right. For example:

... 1>xxx 2>&1

first associates file descriptor 1 with file xxx. It associates file descriptor 2 with the file associated with file descriptor 1 (i.e. xxx). If the order of redirections is reversed, file descriptor 2 is associated with the terminal (assuming file descriptor 1 was originally) and file descriptor 1 is associated with file xxx.

If a command is followed by &, the default standard input for the command is the empty file /dev/null. Otherwise, the environment for executing a command contains the file descriptors of the invoking shell as modified by input/output specifications.

Redirection of output is not allowed in the restricted shell.

Environment

The environment (see environ(5)) is a list of name-value pairs that is passed to an executed program in the same way as a normal argument list. The shell interacts with the environment in several ways. On invocation, the shell scans the environment and creates a parameter for each name found, giving it the corresponding value. Executed commands inherit the same environment. If the user modifies the value of any of these parameters or creates new parameters, none of these affects the environment unless the export command is used to bind the shell's parameter to the environment (see also set -a). To remove a parameter from the environment, use the unset command. The environment seen by any executed command is thus composed of any unmodified name-value pairs originally inherited by the shell, minus any pairs removed by unset, plus any modifications or additions, all of which must be noted in export commands.

The environment for any simple-command can be augmented by prefixing it with one or more assignments to parameters. Thus:

TERM=450 cmd

and

(export TERM; TERM=450; cmd)

are equivalent (as far as the execution of cmd is concerned).

If the -k option is set, all keyword arguments are placed in the environment, even if they occur after the command name. The following first prints a=b c and then c:

echo a=b c 
set -k 
echo a=b c 

Signals

The INTERRUPT and QUIT signals for an invoked command are ignored if the command is followed by & and the command does not override the SIGINT and SIGQUIT signal settings it inherited from /usr/old/bin/sh; otherwise signals have the values inherited by the shell from its parent, with the exception of signal 11 (but see also the trap command below).

If a SIGWINCH signal is received, sh determines the new size of the display area and resets the values of the LINES and COLUMNS variables appropriately. Note that the value of either variable is modified only if that variable exists at the time SIGWINCH is received. sh does not create these variables. Any traps set on SIGWINCH are executed immediately after LINES and COLUMNS are reset.

Execution

Each time a command is executed, the above substitutions are carried out. If the command name matches one of the Special Commands listed below, it is executed in the shell process. If the command name does not match a Special Command, but matches the name of a defined function, the function is executed in the shell process (note how this differs from the execution of shell procedures). The positional parameters $1, $2, .... are set to the arguments of the function. If the command name matches neither a Special Command nor the name of a defined function, a new process is created and an attempt is made to execute the command via exec(2).

The shell parameter PATH defines the search path for the directory containing the command. Alternative directory names are separated by a colon (:). The default path is :/usr/bin (specifying the current directory and /usr/bin, in that order). Note that the current directory is specified by a null path name, which can appear immediately after the equal sign or between the colon delimiters anywhere else in the path list. If the command name contains a / the search path is not used (such commands are not executed by the restricted shell). Otherwise, each directory in the path is searched for an executable file. If the file has execute permissions but is not a directory or an executable object code file, it is assumed to be a script file which is a file of data for an interpreter. If the first two characters of the script file are #!, exec (see exec(2)) expects an interpreter path name to follow. exec then attempts to execute the specified interpreter as a separate process to read the entire script file. If a call to exec fails, /usr/old/bin/sh is spawned to interpret the script file.

A parenthesized command is also executed in a sub-shell. The location in the search path where a command was found is remembered by the shell (to help avoid unnecessary execs later). If the command was found in a relative directory, its location must be re-determined whenever the current directory changes. The shell forgets all remembered locations whenever the PATH variable is changed or the hash -r command is executed (see below).

Special Commands

The following commands are executed in the shell process. Input/output redirection is permitted for these commands. File descriptor 1 is the default output location.

:

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

. file

Read and execute commands from file and return. The search path specified by PATH is used to find the directory containing file. Note that this command does not spawn another shell to execute file, and thus differs in behavior and output from executing file as a shell script. It is not necessary that the execute permission bit be set for file.

break [n]

Exit from the enclosing for or while loop, if any. If n is specified, break n levels.

continue [n]

Resume the next iteration of the enclosing for or while loop. If n is specified, resume at the n-th enclosing loop.

cd [arg]

Change the current directory to arg. The shell parameter HOME is the default arg. The shell parameter CDPATH defines the search path for the directory containing arg. Alternative directory names are separated by a colon (:). The default path is null (meaning the current directory). Note that the current directory is specified by a null path name, which can appear immediately after the equal sign or between the colon delimiters anywhere else in the path list. If arg begins with a / the search path is not used. Otherwise, each directory in the path is searched for arg. The cd command cannot be executed by rsh.

echo [arg ...]

Echo arguments. See echo(1) for usage and description.

eval [arg ...]

The arguments are read as input to the shell and the resulting command(s) executed.

exec [arg ...]

The command specified by the arguments is executed in place of this shell without creating a new process. Input/output arguments can appear and, if no other arguments are given, cause the shell input/output to be modified.

exit [n]

Causes a shell to exit with the exit status specified by n. If n is omitted, the exit status is that of the last command executed (an end-of-file also causes the shell to exit.)

export [name ...]

The given names are marked for automatic export to the environment of subsequently-executed commands. If no arguments are given, a list of names currently included in the environment are printed. Function names cannot be exported.

hash [-r] [name ...]

For each name, the location in the search path of the command specified by name is determined and remembered by the shell. The -r option causes the shell to forget all remembered locations. If no arguments are given, information about remembered commands is presented. hits is the number of times a command has been invoked by the shell process. cost is a measure of the work required to locate a command in the search path. Certain situations require that the stored location of a command be recalculated. Commands for which this will be done are indicated by an asterisk (*) adjacent to the hits information. cost is incremented when the recalculation is done.

newgrp [arg ...]

Equivalent to exec newgrp arg .... See newgrp(1) for usage and description.

pwd

Print the current working directory. read name ... One line is read from the standard input and the first word is assigned to the first name, the second word to the second name, etc., with leftover words assigned to the last name. The return code is 0 unless an end-of-file is encountered.

Note that although the read command is a built-in command and is generally executed directly by the shell, this is not the case when it is used in a pipeline. In a pipeline, a new shell is forked to execute the read command with the result that any shell variables set are not available to the parent shell when the pipeline is finished. This has the effect of making the read command useless in a pipeline.

readonly [name ...]

The given names are marked readonly and the values of the these names cannot be changed by subsequent assignment. If no arguments are given, a list of all readonly names is printed.

return [n]

Causes a function to exit with the return value specified by n. If n is omitted, the return status is that of the last command executed.

set [--aefhkntuvx [arg ...]]

set sets or unsets options, and resets the values of the positional parameters to the args given, if any. The option list is terminated by the first argument that does not begin with - or +, or upon encountering an argument consisting entirely of --. Recognized options are:

-a: Mark variables which are modified or created for export.
-e: Exit immediately if a command exits with a non-zero exit status.
-f: Disable file name generation
-h: Locate and remember function commands as functions are defined (function commands are normally located when the function is executed).
-k: All keyword arguments are placed in the environment for a command, not just those that precede the command name.
-n: Read commands but do not execute them.
-t: Exit after reading and executing one command.
-u: Treat unset variables as an error when substituting.
-v: Print shell input lines as they are read.
-x: Print commands and their arguments as they are executed.
--: Do not change any of the options; useful when $1 is to be set to a string beginning with - or +.

Using \+ rather than - causes these options to be unset. These options can also be used upon invocation of the shell. The current set of options can be found in $-. The remaining arguments are positional parameters and are assigned, in order, to $1, $2, .... If no arguments are given, the values of all names are printed.

shift [n]

The positional parameters from $n+1 ... are renamed $1 .... If n is not given, it is assumed to be 1.

test

Evaluate conditional expressions. See test(1) for usage and description. Note that [...] in an if list is interpreted the same as test .... There must be blanks around the brackets.

times

Print the accumulated user and system times for processes run from the shell.

trap [arg] [n] ...

The command arg is a command to be read and executed when the shell receives signal(s) n. (Note that arg is scanned once when the trap is set and once when the trap is taken.) Trap commands are executed in order of signal number. Any attempt to set a trap on a signal that was ignored on entry to the current shell is ineffective. An attempt to trap on signal 11 (memory fault) or signal 18 (death of child) produces an error. If arg is absent then all trap(s) n are reset to their original values. If arg is the null string, this signal is ignored by the shell and by the commands it invokes. If n is 0, the command arg is executed on exit from the shell. The trap command with no arguments prints a list of commands associated with each signal number.

type [name ...]

For each name, indicate how it would be interpreted if used as a command name.

ulimit [-f [n]]

If the -f n option is used, a size limit of n blocks is imposed on files written by child processes (files of any size can be read). If n is not specified, the current limit is printed. If no option is specified, -f is assumed.

umask [nnn]

The user file-creation mask is set to nnn (see umask(2)). If nnn is omitted, the current value of the mask is printed.

unset [name ...]

For each name, remove the corresponding variable or function. The variables PATH, PS1, PS2, MAILCHECK, and IFS cannot be unset.

wait [n]

Wait for the specified process and report its termination status. If n is not given all currently active child processes are waited for and the return code is zero.

Invocation

Options can be specified in a single argument or in multiple arguments, but in all cases each option argument must begin with -. (All options except c, s, i, and r can also be prefaced with a +, which turns off the associated option or options, but this is redundant when invoking a new shell because all options are turned off by default).

If the first character of argument zero is -, commands are initially read from /etc/profile, then from $HOME/.profile, if the files exist. Thereafter, commands are read as described below.

The options below are interpreted by the shell at invocation (thus they cannot be used with the set command). Unless the -c or -s option is specified, the first non-option argument is assumed to be the name of a file containing commands, and the remaining arguments are passed as positional parameters to that command file.

-c string: If the -c option is present then commands are read from string.
-s: If the -s option is present or if no arguments remain, commands are read from the standard input. Any remaining arguments specify the positional parameters. Shell output (except for "Special Commands" ) is written to file descriptor 2.
-i: If the -i option is present or if the shell input and output are attached to a terminal, this shell is interactive. In this case TERMINATE is ignored (so that kill 0 does not kill an interactive shell) and INTERRUPT is caught and ignored (so that wait is interruptible). In all cases, QUIT is ignored by the shell.
-r: If the -r option is present the shell is a restricted shell.

The remaining options and arguments are described under the set command above.

rsh Only

rsh is used to set up login names and execution environments whose capabilities are more controlled than those of the standard shell. The actions of rsh are identical to those of sh, except that the following are disallowed:

Changing directory (see cd(1)),
Setting the value of $PATH,
Specifying path or command names containing /,
Redirecting output (> and >>).

The restrictions above are enforced after .profile is interpreted.

When a command to be executed is found to be a shell procedure, rsh invokes sh to execute it. Thus, it is possible to provide to the end-user shell procedures that have access to the full power of the standard shell, while imposing a limited menu of commands; this scheme assumes that the end-user does not have write and execute permissions in the same directory.

The net effect of these rules is that the writer of the .profile has complete control over user actions, by performing guaranteed setup actions and leaving the user in an appropriate directory (probably not the login directory).

The system administrator often sets up a directory of commands (such as /usr/rbin) that can be safely invoked by rsh. Commands such as vi, sh, ksh, csh, and such that can break rsh restrictions should not be included in that directory. Some systems also provide a restricted editor red.

EXTERNAL INFLUENCES

Environment Variables

LC_COLLATE determines the collating sequence used in evaluating pattern matching notation for file name generation.

LC_CTYPE determines the interpretation of text as single and/or multi-byte characters, the classification of characters as letters, and the characters matched by character class expressions in pattern matching notation.

LANG determines the language in which messages are displayed.

If LC_COLLATE or LC_CTYPE is not specified in the environment or is set to the empty string, the value of LANG is used as a default for each unspecified or empty variable. If LANG is not specified or is set to the empty string, a default of "C" (see lang(5)) is used instead of LANG. If any internationalization variable contains an invalid setting, sh behaves as if all internationalization variables are set to "C". See environ(5).

International Code Set Support

Single- and multi-byte character code sets are supported.

RETURN VALUE

The error codes returned by the shell are:

0: Success.
1: Built-in command failure (see Special Commands).
2: Syntax error.
3: Signal received that is not trapped.

If the shell is non-interactive, it terminates and passes one of the above as its exit status. If it is interactive, it does not terminate, but $? is set to one of the above values.

Whenever a child process of the shell dies due to a signal, the shell returns an exit status of 80 hexadecimal plus the number of the signal.

WARNINGS

If a command is executed and a command having the same name is installed in a directory in the search path before the directory where the original command was found, the shell continues to exec the original command. Use the hash command to correct this situation.

When the shell encounters >>, it does not open the file in append mode. Instead, it opens the file for writing and seeks to the end.

If you move the current directory or one above it, pwd cannot give the correct response. Use the cd command with a full path name to correct this situation.

The command readonly (without arguments) produces the same output as the command export.

Failure (non-zero exit status) of a special command preceding a || symbol prevents the list following || from executing.

In an international environment, character ordering is determined by the setting of LC_COLLATE, rather than by the binary ordering of character values in the machine collating sequence. This brings with it certain attendant dangers, particularly when using range expressions in file-name-generation patterns. For example, the command,

rm [a-z]* 

might be expected to match all file names beginning with a lowercase alphabetic character. However, if dictionary ordering is specified by LC_COLLATE, it also matches file names beginning with an uppercase character (as well as those beginning with accented letters). Conversely, it fails to match letters collated after z in languages such as Norwegian.

The correct (and safe) way to match specific character classes in an international environment is to use a pattern of the form:

rm [[:lower:]]* 

This uses LC_CTYPE to determine character classes and works predictably for all supported languages and codesets. For shell scripts produced on non-internationalized systems (or without consideration for the above dangers), it is recommended that they be executed in a non-NLS environment. This requires that LANG, LC_COLLATE, etc., be set to "C" or not set at all.

sh implements command substitution by creating a pipe between itself and the command. If the root file system is full, the substituted command cannot write to the pipe. As a result, the shell receives no input from the command, and the result of the substitution is null. In particular, using command substitution for variable assignment under such circumstances results in the variable being silently assigned a NULL value.

The signal SIGSEGV should not be blocked when executing sh.

sh reserves file descriptor 59 for internal use. Reducing the number of available file descriptors below 60 causes sh to fail.

Each time a function is executed in a shell script, any arguments given to the function overwrite the values of the positional parameters for the entire script. If the values of the positional parameters must be preserved, they must be explicitly saved before each function call.

AUTHOR

sh was developed by AT&T and HP.

FILES

$HOME/.profile 
/dev/null 
/etc/profile 
/tmp/sh* 

STANDARDS CONFORMANCE

.: SVID2, SVID3, XPG2, XPG3

:: SVID2, SVID3, XPG2, XPG3

break: SVID2, SVID3, XPG2, XPG3

case: SVID2, SVID3, XPG2, XPG3

continue: SVID2, SVID3, XPG2, XPG3

eval: SVID2, SVID3, XPG2, XPG3

exec: SVID2, SVID3, XPG2, XPG3

exit: SVID2, SVID3, XPG2, XPG3

export: SVID2, SVID3, XPG2, XPG3

for: SVID2, SVID3, XPG2, XPG3

if: SVID2, SVID3, XPG2, XPG3

read: SVID2, SVID3, XPG2, XPG3

return: SVID2, SVID3, XPG2, XPG3

rsh: SVID2, SVID3

set: SVID2, SVID3, XPG2, XPG3

sh: SVID2, SVID3, XPG2, XPG3

shift: SVID2, SVID3, XPG2, XPG3

time: SVID2, SVID3, XPG2, XPG3

trap: SVID2, SVID3, XPG2, XPG3

unset: SVID2, SVID3, XPG2, XPG3

until: SVID2, SVID3, XPG2, XPG3

while: SVID2, SVID3, XPG2, XPG3