+++ /dev/null
-.\"
-.\" Sccsid @(#)sh.1 1.14 (gritter) 7/13/05
-.\" Derived from sh(1) and test(1), Unix 7th edition:
-.\" Copyright(C) Caldera International Inc. 2001-2002. All rights reserved.
-.\"
-.\" Redistribution and use in source and binary forms, with or without
-.\" modification, are permitted provided that the following conditions
-.\" are met:
-.\" Redistributions of source code and documentation must retain the
-.\" above copyright notice, this list of conditions and the following
-.\" disclaimer.
-.\" Redistributions in binary form must reproduce the above copyright
-.\" notice, this list of conditions and the following disclaimer in the
-.\" documentation and/or other materials provided with the distribution.
-.\" All advertising materials mentioning features or use of this software
-.\" must display the following acknowledgement:
-.\" This product includes software developed or owned by Caldera
-.\" International, Inc.
-.\" Neither the name of Caldera International, Inc. nor the names of
-.\" other contributors may be used to endorse or promote products
-.\" derived from this software without specific prior written permission.
-.\"
-.\" USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
-.\" INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
-.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-.\" ARE DISCLAIMED. IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE
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-.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
-.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
-.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
-.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
-.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-.\"
-.TH SH 1 "7/13/05" "Heirloom Bourne Shell" "User Commands"
-.SH NAME
-sh, jsh \- the standard command interpreter
-.SH SYNOPSIS
-\fBsh\fR [\fB\-acefhikmnprstuvx\fR] [\fIarg\fR] ...
-.br
-\fBjsh\fR [\fB\-acefhikmnprstuvx\fR] [\fIarg\fR] ...
-.SH DESCRIPTION
-.I Sh
-is a command programming language
-that executes commands read from a terminal
-or a file.
-See the
-.I invocation
-section
-for the meaning of arguments to the shell.
-.SS Commands
-A
-.I simple-command
-is a sequence of non blank
-.I words
-separated by blanks (a blank is a
-.B tab
-or a
-.BR space ).
-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
-.IR exec (2)).
-The
-.I value
-of a simple-command is its exit status
-if it terminates normally or 200+\fIstatus\fP if
-it terminates abnormally (see
-.IR signal (2)
-for a list of
-status values).
-.PP
-A
-.I pipeline
-is a sequence of one or more
-.I commands
-separated by
-.B \(or.
-The standard output of each command but the last
-is connected by a
-.IR pipe (2)
-to the standard input of the next command.
-Each command is run as a separate process;
-the shell waits for the last command to terminate.
-The
-.I value
-of a pipeline
-is the exit status of its last command.
-.PP
-A
-.I list
-is a sequence of one or more
-.I pipelines
-separated by
-.BR ; ,
-.BR & ,
-.B &&
-or
-.B \(or\|\(or
-and optionally terminated by
-.B ;
-or
-.BR & .
-.B ;
-and
-.B &
-have equal precedence
-which is lower than that of
-.B &&
-and
-.BR \(or\|\(or ,
-.B &&
-and
-.B \(or\|\(or
-also have equal precedence.
-A semicolon causes sequential execution; an ampersand causes
-the preceding
-.I pipeline
-to be executed without waiting for it to finish.
-The symbol
-.B &&
-.RB ( \(or\|\(or )
-causes the
-.I list
-following to be executed only if the preceding
-.I pipeline
-returns a zero (non zero) value.
-Newlines may appear in a
-.I list,
-instead of semicolons,
-to delimit commands.
-.PP
-A
-.B #
-at the beginning of a word
-starts a comment and
-causes the rest of the line to be ignored.
-.PP
-A
-.I command
-is either a simple-command
-or one of the following.
-The value returned by a command is that of the
-last simple-command executed in the command.
-.TP
-\fBfor \fIname\fR [\fBin \fIword\fR ...] \fBdo \fIlist \fBdone\fR
-Each time a
-.B for
-command is executed
-.I name
-is set to the next word in the
-.B for
-word list
-If
-.BI in \ word
-\&...
-is omitted then
-.B
-in "$@"
-is assumed.
-Execution ends when there are no more words in the list.
-.TP
-\fBcase \fIword \fBin\fR [\fIpattern \fR[\fB\(or \fIpattern \fR] ... \fB) \fIlist \fB;;\fR] ... \fBesac\fR
-A
-.B case
-command executes the
-.I list
-associated with the first
-pattern that matches
-.I word.
-The form of the patterns is
-the same as that used for
-file name generation.
-.TP
-\fBif \fIlist \fBthen \fIlist\fR [\fBelif \fIlist \fBthen \fIlist\fR] ... [\fBelse \fIlist\fR] \fBfi\fR
-The
-.I list
-following
-.B if
-is executed and if it returns zero the
-.I list
-following
-.B then
-is executed.
-Otherwise, the
-.I list
-following
-.B elif
-is executed and if its value is zero
-the
-.I list
-following
-.B then
-is executed.
-Failing that the
-.B else
-.I list
-is executed.
-.TP
-\fBwhile \fIlist\fR [\fBdo \fIlist\fR] \fBdone\fR
-A
-.B while
-command repeatedly executes the
-.B while
-.I list
-and if its value is zero executes the
-.B do
-.I list;
-otherwise the loop terminates.
-The value returned by a
-.B while
-command is that
-of the last executed command in the
-.B do
-.I list.
-.B until
-may be used in place of
-.B while
-to negate
-the loop termination test.
-.TP
-.BI ( " list " )
-Execute
-.I list
-in a subshell.
-.TP
-.BI { " list" "; }"
-.I list
-is simply executed.
-.TP
-\fIname\fB() { \fIlist\fB; }\fR
-Defines the shell function
-.IR name.
-Each time when
-.I name
-is recognized as a command,
-.I list
-is executed,
-with the positional parameters
-.IR $1 ", " $2 ...
-set to the arguments of the command.
-After the function returns,
-the previous positional parameters are restored.
-.PP
-The following words
-are only recognized as the first word of a command
-and when not quoted.
-.IP
-.B
-if then else elif fi case in esac for while until do done { }
-.SS "Command substitution"
-The standard output from a command enclosed in
-a pair of grave accents
-.RB ( \`\|\` )
-may be used as part or all
-of a word;
-trailing newlines are removed.
-.SS "Parameter substitution"
-The character
-.B $
-is used to introduce substitutable
-parameters.
-Positional parameters may be assigned values by
-.BR set .
-Variables may be set by writing
-.IP
-.IB name = value
-[
-.IB name = value
-] ...
-.TP
-$\fB\|{\fIparameter\fB\|}\fR
-A
-.I parameter
-is a sequence of letters, digits or underscores (a
-.IR name ),
-a digit,
-or any of the characters
-.B
-* @ # ? \- $ !\|.
-The value, if any, of the parameter is substituted.
-The braces are required only when
-.I parameter
-is followed by a letter, digit, or underscore
-that is not to be interpreted as part of its name.
-If
-.I parameter
-is a digit then it is a positional parameter.
-If
-.I parameter
-is
-.BR * " or" " @"
-then all the positional
-parameters, starting with
-.SM
-.BR $1 ,
-are substituted
-separated by spaces.
-.SM
-.B $0
-is set from argument zero when the shell
-is invoked.
-.TP
-$\fB\|{\fIparameter:\-word\|\fB}\fR
-If
-.I parameter
-is set and not empty then substitute its value;
-otherwise substitute
-.I word.
-.TP
-$\fB\|{\fIparameter:=word\|\fB}\fR
-If
-.I parameter
-is not set and not empty then set it to
-.I word;
-the value of the parameter is then substituted.
-Positional parameters may not be assigned to
-in this way.
-.TP
-$\fB\|{\fIparameter:?word\|\fB}\fR
-If
-.I parameter
-is set and not empty then substitute its value;
-otherwise, print
-.I word
-and exit from the shell.
-If
-.I word
-is omitted then a standard message is printed.
-.TP
-$\fB\|{\fIparameter:+word\|\fB}\fR
-If
-.I parameter
-is set and not empty then substitute
-.I word;
-otherwise substitute nothing.
-.PP
-If the
-.B :
-is omitted,
-the substitutions are only executed
-if the
-.I parameter
-is set, even if it is empty.
-.PP
-In the above
-.I word
-is not evaluated unless it is
-to be used as the substituted string.
-(So that, for example,
-echo ${d\-\`pwd\`}
-will only execute
-.I pwd
-if
-.I d
-is unset.)
-.PP
-The following
-.I parameters
-are automatically set by the shell.
-.RS
-.TP
-.B #
-The number of positional parameters in decimal.
-.PD 0
-.TP
-.B \-
-Options supplied to the shell on invocation or by
-.BR set .
-.TP
-.B ?
-The value returned by the last executed command
-in decimal.
-.TP
-.B $
-The process number of this shell.
-.TP
-.B !
-The process number of the last background command invoked.
-.PD
-.RE
-.PP
-The following
-.I parameters
-are used by the shell:
-.RS
-.TP
-.PD 0
-.SM
-.B CDPATH
-The search path for the
-.I cd
-command (see above).
-.TP
-.SM
-.B HOME
-The default argument (home directory) for the
-.B cd
-command.
-.TP
-.SM
-.B OPTARG
-The value of the last option argument processed by the
-.I getopts
-special command.
-.TP
-.SM
-.B OPTIND
-The index of the last option processed by the
-.I getopts
-special command.
-.TP
-.SM
-.B PATH
-The search path for commands (see
-.BR execution ).
-.TP
-.SM
-.B MAIL
-If this variable is set to the name of
-a mail file then the shell informs the user of
-the arrival of mail in the specified file.
-.TP
-.SM
-.B MAILCHECK
-If this variable is set,
-it is interpreted as a value in seconds
-to wait between checks for new mail.
-The default is 600 (10 minutes).
-If the value is zero,
-mail is checked before each prompt.
-.TP
-.SM
-.B MAILPATH
-A colon-separated list of files
-that are checked for new mail.
-.SM MAIL
-is ignored if this variable is set.
-.SM
-.TP
-.SM
-.B PS1
-Primary prompt string, by default `$ '.
-.TP
-.SM
-.B PS2
-Secondary prompt string, by default `> '.
-.TP
-.SM
-.B IFS
-Internal field separators,
-normally
-.BR space ,
-.BR tab ,
-and
-.BR newline .
-.TP
-.SM
-.BR LANG ", " LC_ALL
-See
-.IR locale (7).
-.TP
-.SM
-.B LC_CTYPE
-Affects the mapping of bytes to characters
-for file name generation,
-for the interpretation of `\e',
-and for handling
-.SM $IFS.
-.TP
-.SM
-.B SHACCT
-If this variable is set in the initial environment passed to the shell
-and points to a file writable by the user,
-accounting statistics are written to it.
-.TP
-.SM
-.B TIMEOUT
-The shell exists when prompting for input
-if no command is entered
-for more than the given value in seconds.
-A value of zero means no timeout
-and is the default.
-.PD
-.RE
-.SS "Blank interpretation"
-After parameter and command substitution,
-any results of substitution are scanned for internal field separator
-characters (those found in
-.SM
-.BR $IFS \*S)
-and split into distinct arguments where such characters are found.
-Explicit null arguments ("" or \'\') are retained.
-Implicit null arguments
-(those resulting from
-.I parameters
-that have no values) are removed.
-.SS "File name generation"
-Following substitution, each command word is scanned for
-the characters
-.BR * ,
-.B ?
-and
-.B [.
-If one of these characters appears
-then the word is regarded as a pattern.
-The word is replaced with alphabetically sorted file names that match the pattern.
-If no file name is found that matches the pattern then
-the word is left unchanged.
-The character
-.B .
-at the start of a file name
-or immediately following a
-.BR / ,
-and the character
-.BR / ,
-must be matched explicitly.
-.TP
-.B *
-Matches any string, including the null string.
-.PD 0
-.TP
-.B ?
-Matches any single character.
-.TP
-.B [...]
-Matches any one of the characters
-enclosed.
-A pair of characters separated by
-.B \-
-matches any
-character lexically between the pair.
-.TP
-.B [!...]
-Matches any character except the enclosed ones.
-.PD
-.SS "Quoting"
-The following characters have a special meaning to the shell
-and cause termination of a word unless quoted.
-.PP
- \fB; & ( ) \(or ^ < > newline space tab\fP
-.PP
-A character may be
-.I quoted
-by preceding
-it with a
-.B
-\\\|.
-.B \\\\newline
-is ignored.
-All characters enclosed between a pair of quote marks (\fB\'\|\'\fP),
-except a single quote,
-are quoted.
-Inside double quotes
-(\fB"\|"\fP)
-parameter and command substitution occurs and
-.B
-\\
-quotes the characters
-.B
-\\ \` "
-and
-.BR $ \|.
-.PP
-.B
-"$*"
-is equivalent to
-.SM
-.B
-"$1 $2 ..."
-whereas
-.br
-.B
-"$@"
-is equivalent to
-.SM
-.B
-"$1" "$2" ... .
-.SS "Prompting"
-When used interactively,
-the shell prompts with the value of
-.SM $PS1
-before reading a command.
-If at any time a newline is typed and further input is needed
-to complete a command then the secondary prompt
-(\s-1$PS2\s0)
-is issued.
-.SS "Input and output"
-Before a command is executed its input and output
-may be redirected using a special notation interpreted by the shell.
-The following may appear anywhere in a simple-command
-or may precede or follow a
-.I command
-and are not passed on to the invoked command.
-Substitution occurs before
-.I word
-or
-.I digit
-is used.
-.TP
-\fB<\fI\|word\fP
-Use file
-.I word
-as standard input (file descriptor 0).
-.PD
-.TP
-\fB>\fI\|word\fP
-Use file
-.I word
-as standard output (file descriptor 1).
-If the file does not exist then it is created;
-otherwise it is truncated to zero length.
-.TP
-\fB>>\fI\|word\fP
-Use file
-.I word
-as standard output.
-If the file exists then output is appended (by seeking to the end);
-otherwise the file is created.
-.TP
-\fB<<\fR[\fB\-\fR]\fI\|word\fP
-The shell input is read up to a line the same as
-.IR word ,
-or end of file.
-The resulting document becomes
-the standard input.
-If any character of
-.I word
-is quoted then no interpretation
-is placed upon the characters of the document;
-otherwise, parameter and command substitution occurs,
-.B
-\\newline
-is ignored,
-and
-.B
-\\
-is used to quote the characters
-.B
-\\ $ \`
-and the first character of
-.I word.
-The optional
-.B \-
-causes leading tabulator character to be stripped
-from the resulting document;
-.I word
-may then also be prefixed by a tabulator.
-.TP
-\fB<\|&\|\fIdigit\fP
-The standard input is duplicated from file descriptor
-.I digit;
-see
-.IR dup (2).
-Similarly for the standard output using >\|.
-.TP
-\fB<\|&\|\-
-The standard input is closed.
-Similarly for the standard output using >\|.
-.PD
-.PP
-If one of the above is preceded by a digit
-then the
-file descriptor created is that specified
-by the digit
-(instead of the default 0 or 1).
-For example,
-.PP
- \&... 2>&1
-.PP
-creates file descriptor 2 to be a duplicate
-of file descriptor 1.
-.PP
-If a command is followed by
-.B &
-then the default standard input
-for the command
-is the empty file
-(/dev/null),
-unless job control is enabled.
-Otherwise, the environment for the execution of a command contains the
-file descriptors of the invoking shell as modified by input
-output specifications.
-.SS "Environment"
-The environment
-is a list of name-value pairs that is passed to
-an executed program in the same way as a normal argument list;
-see
-.IR exec (2)
-and
-.IR environ (5).
-The shell interacts with the environment in several ways.
-On invocation, the shell scans the environment
-and creates a
-.I parameter
-for each name found,
-giving it the corresponding value.
-Executed commands inherit the same environment.
-If the user modifies the values of these
-.I parameters
-or creates new ones,
-none of these affects the environment
-unless the
-.I export
-command is used to bind the shell's
-.I parameter
-to the environment.
-The environment seen by any executed command is thus composed
-of any unmodified name-value pairs originally inherited by the shell,
-plus any modifications or additions,
-all of which must be noted in
-.I export
-commands.
-.PP
-The environment for any
-.I simple-command
-may be augmented by prefixing it with one or more assignments to
-.I parameters.
-Thus these two lines are equivalent
-.IP
-TERM=450 cmd args
-.br
-(export TERM; TERM=450; cmd args)
-.PP
-If the
-.I \-k
-flag is set,
-.I all
-keyword arguments are placed in the environment,
-even if the occur after the command name.
-The following prints `a=b c' and `c':
-.nf
-echo a=b c
-set \-k
-echo a=b c
-.fi
-.SS "Signals"
-The INTERRUPT and QUIT signals for an invoked
-command are ignored if the command is followed by
-.B &
-(unless job control is enabled);
-otherwise signals have the values
-inherited by the shell from its parent.
-(But see also
-.IR trap. )
-.SS "Execution"
-Each time a command is executed the above substitutions
-are carried out.
-The shell then first looks if a function with the command name was defined;
-if so, it is chosen for execution.
-Otherwise, except for the `special commands' listed below a new
-process is created and
-an attempt is made to execute the command via an
-.IR exec (2).
-.PP
-The shell parameter
-.SM $PATH
-defines the search path for
-the directory containing the command.
-Each alternative directory name is separated by
-a colon
-.RB ( : ).
-The default path is
-`/usr/5bin:/bin:/usr/bin:'.
-If the command name contains a / then the search path
-is not used.
-Otherwise, each directory in the path is
-searched for an executable file.
-If the file has execute permission but is not an
-.I a.out
-file,
-it is assumed to be a file containing shell commands.
-A subshell (i.e., a separate process) is spawned to read it.
-A parenthesized command is also executed in
-a subshell.
-.SS "Special commands"
-The following commands are executed in the shell process itself:
-.TP
-.B :
-No effect; the command does nothing.
-.PD 0
-.TP
-.BI . \ file
-Read and execute commands from
-.I file
-and return.
-The search path
-.SM $PATH
-is used to find the directory containing
-.IR file .
-.TP
-\fBbreak\fR [\fIn\fR]
-Exit from the enclosing
-.I for
-or
-.I while
-loop, if any.
-If
-.I n
-is specified then break
-.I n
-levels.
-.TP
-\fBcontinue\fR [\fIn\fR]
-Resume the next iteration of the enclosing
-.I for
-or
-.I while
-loop.
-If
-.I n
-is specified then resume at the
-.IR n -th
-enclosing loop.
-.TP
-\fBcd\fR [\fIarg\fR]
-Change the current directory to
-.I arg.
-The shell
-parameter
-.SM $HOME
-is the default
-.IR arg .
-If no directory
-.I arg
-is found and the
-.SM $CDPATH
-parameter contains a list of directories separated by colons,
-each of these directories is used as a prefix to
-.I arg
-in the given order,
-and the current directory is set to the first one that is found.
-.\" BEGIN SPELL
-.IP
-If there has still no suitable directory been found,
-an interactive shell will try to fix spelling errors
-and propose an alternative directory name:
-.sp
-.nf
- $ cd /usf/lb
- cd /usr/lib? \fIy\fP
- ok
-.fi
-.sp
-If the answer is `y' or anything other than `n',
-the shell will set the current directory to the one proposed.
-.\" END SPELL
-.TP
-\fBecho\fR [\fIarg \fR...]
-Each
-.I arg
-is printed to standard output;
-afterwards, a newline is printed.
-The following escapes sequences are recognized in
-.IR arg :
-.PD 0
-.RS
-.TP 7n
-.B \eb
-Prints a backspace character.
-.TP
-.B \ec
-Causes the command to return immediately.
-Any following characters are ignored,
-and the terminating newline is not printed.
-.TP
-.B \ef
-Prints a formfeed character.
-.TP
-.B \en
-Prints a newline character.
-.TP
-.B \er
-Prints a carriage-return character.
-.TP
-.B \et
-Prints a tabulator character.
-.TP
-.B \ev
-Prints a vertical tabulator character.
-.TP
-.B \e\e
-Prints a backslash character.
-.TP
-.BI \e0 nnn
-Prints the character (byte) with octal value
-.IR nnn .
-.PD
-.PP
-If
-.I /usr/ucb
-precedes
-.I /usr/5bin
-or
-.I /usr/bin
-in the current setting of the
-.SM $PATH
-variable and the first argument is
-.BR \-n ,
-the terminating newline is not printed,
-and no escape sequences are recognized.
-If the
-.B $SYSV3
-variable is set in the initial environment passed to the shell,
-the
-.I \-n
-argument is also interpreted,
-but escape sequences are processed as usual.
-.RE
-.TP
-\fBeval\fR [\fIarg \fR...]
-The arguments are read as input
-to the shell
-and the resulting command(s) executed.
-.TP
-\fBexec\fR [\fIarg \fR...]
-The command specified by
-the arguments is executed in place of this shell
-without creating a new process.
-Input output arguments may appear and if no other
-arguments are given cause the shell input
-output to be modified.
-.TP
-\fBexit\fR [\fIn\fR]
-Causes the shell to exit
-with the exit status specified by
-.I n.
-If
-.I n
-is omitted then the exit status is that of the last command executed.
-(An end of file will also exit from the shell.)
-.TP
-\fBexport\fR [\fIname\fR ...]
-The given names are marked
-for automatic export to the
-.I environment
-of subsequently-executed commands.
-If no arguments are given then a list of
-exportable names is printed.
-.\".TP
-.\"\fBlogin\fR [\fIarg\fR ...]
-.\"Equivalent to `exec login arg ...'.
-.TP
-\fBgetopts optstring variable\fR [\fIarg\fR ...]
-Retrieves options and option-arguments
-from
-.I arg
-(or the positional parameters)
-similar to
-.IR getopt (3).
-.I optstring
-is a list of characters (bytes);
-each character represents an option letter.
-A character followed by
-.B :
-indicates that the option has an argument.
-Calling
-.I getopts
-repeatedly causes one option to be retrieved per call.
-The index of the current option is stored in the variable
-.SM OPTIND;
-it is initialized to 1 when the shell starts.
-The option-argument, if any, is stored in the
-.SM OPTARG
-variable.
-The option character is stored in the
-.I variable
-named.
-When the end of the options is reached,
-.I getopts
-returns with a non-zero value.
-A missing argument or an illegal option
-also causes a non-zero return value,
-and an error message is printed to standard error.
-.TP
-\fBhash\fR [\fB\-r\fR] [\fIname\fR ...]
-The shell maintains a hash table
-of the locations of external commands.
-If
-.I name
-arguments are given,
-each one is looked up and is inserted into the table if it is found.
-With the
-.I \-r
-option, the table is cleared.
-Otherwise,
-a list of the commands currently in the table is printed.
-.TP
-\fBnewgrp\fR [\fIarg \fR...]
-Equivalent to `exec newgrp arg ...'.
-.TP
-.B pwd
-Prints the name of the current directory.
-.TP
-\fBread\fR [\fB\-r\fR] \fIname\fR ...
-One line is read from the standard input;
-successive words of the input are assigned to the
-variables
-.I name
-in order,
-with leftover words to the last variable.
-The return code is 0 unless the end-of-file is encountered.
-Normally, backslashes in the line read escape the following character;
-this is inhibited if the
-.B \-r
-option is given.
-.TP
-\fBreadonly\fR [\fIname \fR...]
-The given names are marked readonly and
-the values of the these names may not be changed
-by subsequent assignment.
-If no arguments are given then a list
-of all readonly names is printed.
-.TP
-\fBreturn\fR [\fIn\fR]
-Return from a shell function to the execution level above.
-With the argument
-.IR n ,
-the special variable
-.I $?
-is set to the given value.
-.TP
-\fBset\fR [\fB\-\-aefhknptuvx\fR [\fIarg \fR...]]
-.RS
-.PD 0
-.TP 6n
-.B \-\-
-No effect;
-useful if the first
-.I arg
-begins with
-.IR \- .
-.TP
-.B \-a
-Export any variables that are modified or created from now on.
-.TP
-.B \-e
-If non interactive then exit immediately if a command fails.
-.TP
-.B \-f
-File name generation is disabled.
-.TP
-.B \-h
-When a function is defined,
-look up all external commands it contains as described for the
-.I hash
-special command.
-Normally, these commands are looked up when they are executed.
-.TP
-.B \-k
-All keyword arguments are placed in the environment for a command,
-not just those that precede the command name.
-.TP
-.B \-m
-Enables job control (see below).
-.TP
-.B \-n
-Read commands but do not execute them.
-.TP
-.B \-p
-Makes the shell privileged.
-A privileged shell does not execute the system and user profiles;
-if an non-privileged shell (the default)
-has an effective user or group id
-different to its real user or group id
-or if it has an effective user or group id below 100,
-it resets its effective user or group id, respectively,
-to the corresponding real id at startup.
-.TP
-.B \-t
-Exit after reading and executing one command.
-.TP
-.B \-u
-Treat unset variables as an error when substituting.
-.TP
-.B \-v
-Print shell input lines as they are read.
-.TP
-.B \-x
-Print commands and their arguments as they are executed.
-.TP
-.B \-
-Turn off the
-.B \-x
-and
-.B \-v
-options.
-.PD
-.PP
-These flags can also be used upon invocation of the shell.
-The current set of flags may be found in
-.BR $\- .
-.PP
-If
-.B +
-is used instead of
-.IR \- ,
-the given flags are disabled.
-.PP
-Remaining arguments are positional
-parameters and are assigned, in order, to
-.SM
-.BR $1 ,
-.SM
-.BR $2 ,
-etc.
-If no arguments are given then the values
-of all names are printed.
-.RE
-.TP
-\fBshift\fR [\fIn\fR]
-The positional parameters from
-.SM
-.BR $2 ...
-are renamed
-.SM
-.BR $1 ...
-The
-.I n
-argument causes a shift by the given number,
-i.\|e.
-.SM
-.BI $ n+1
-is renamed to
-.SM
-.B $1
-and so forth.
-.TP
-.B times
-Print the accumulated user and system times for
-processes run from the shell.
-.TP
-\fBtest\fR [\fIexpr\fP]
-.I test
-evaluates the expression
-.IR expr ,
-and if its value is true then returns zero exit status; otherwise, a
-non zero exit status is returned.
-.I test
-returns a non zero exit if there are no arguments.
-.RS
-.PP
-The following primitives are used to construct
-.IR expr :
-.PD 0
-.TP 12n
-.BR \-r " file"
-true if the file exists and is readable.
-.TP
-.BR \-w " file"
-true if the file exists and is writable.
-.TP
-.BR \-u " file"
-true if the file exists and has the setuid bit set.
-.TP
-.BR \-g " file"
-true if the file exists and has the setgid bit set.
-.TP
-.BR \-k " file"
-true if the file exists and has the sticky bit set.
-.TP
-.BR \-f " file"
-true if the file exists and is a regular file
-(or any file other than a directory if
-.I /usr/ucb
-occurs early in the current
-.SM $PATH
-parameter).
-.TP
-.BR \-d " file"
-true if the file exists and is a directory.
-.TP
-.BR \-h " file"
-true if the file exists and is a symbolic link.
-.TP
-.BR \-L " file"
-true if the file exists and is a symbolic link.
-.TP
-.BR \-p " file"
-true if the file exists and is a named pipe.
-.TP
-.BR \-b " file"
-true if the file exists and is a block device.
-.TP
-.BR \-c " file"
-true if the file exists and is a character device.
-.TP
-.BR \-s " file"
-true if the file exists and has a size greater than zero.
-.TP
-.BR \-t " [fildes]"
-true if the open file whose file descriptor number is
-.I fildes
-(1 by default)
-is associated with a terminal device.
-.TP
-.BR \-z " s1"
-true if the length of string
-.I s1
-is zero.
-.TP
-.BR \-n " s1"
-true if the length of the string
-.I s1
-is nonzero.
-.TP
-.RB s1 " = " s2
-true
-if the strings
-.I s1
-and
-.I s2
-are equal.
-.TP
-.RB s1 " != " s2
-true
-if the strings
-.I s1
-and
-.I s2
-are not equal.
-.TP
-s1
-true if
-.I s1
-is not the null string.
-.TP
-.RB n1 " \-eq " n2
-true if the integers
-.I n1
-and
-.I n2
-are algebraically equal.
-Any of the comparisons
-.BR \-ne ,
-.BR \-gt ,
-.BR \-ge ,
-.BR \-lt ,
-or
-.BR \-le
-may be used in place of
-.BR \-eq .
-.PD
-.PP
-These primaries may be combined with the
-following operators:
-.PD 0
-.TP 12n
-.B !
-unary negation operator
-.TP
-.B \-a
-binary
-.I and
-operator
-.TP
-.B \-o
-binary
-.I or
-operator
-.TP
-.TP
-.BR "( " "expr" " )"
-parentheses for grouping.
-.PD
-.PP
-.B \-a
-has higher precedence than
-.B \-o.
-Notice that all the operators and flags are separate
-arguments to
-.IR test .
-Notice also that parentheses are meaningful
-as command separators and must be escaped.
-.RE
-.TP
-\fBtrap\fR [\fIarg\fR] [\fIn\fR|\fIname\fR] ...
-.I Arg
-is a command to be read and executed when the shell
-receives signal(s)
-.I n.
-(Note that
-.I 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.
-If
-.I arg
-is absent then all trap(s)
-.I n
-are reset
-to their original values.
-If
-.I arg
-is the null
-string then this signal is ignored by the shell and by invoked commands.
-If
-.I n
-is 0 then the command
-.I arg
-is executed
-on exit from the shell,
-otherwise upon receipt of signal
-.I n
-as numbered in
-.IR signal (2).
-.I Trap
-with no arguments prints a list
-of commands associated with each signal number.
-A symbolic
-.I name
-can be used instead of the
-.I n
-argument;
-it is formed by the signal name in the `C' language
-minus the
-.SM SIG
-prefix,
-e.\|g.
-.SM TERM
-for
-.SM SIGTERM.
-.SM EXIT
-is the same as a `0' argument.
-.TP
-\fBtype\fI name\fR ...
-For each
-.IR name ,
-prints if it would be executed as a shell function,
-as a special command,
-or as an external command.
-In the last case, the full path name to the command is also printed.
-.TP
-\fBulimit\fP [\fB\-\fP[\fBHS\fP][\fBa\fP|\fBcdfmnstuv\fP]]
-.PD 0
-.TP
-\fBulimit\fP [\fB\-\fP[\fBHS\fP][\fBc\fP|\fBd\fP|\fBf\fP|\fBm\fP|\fBn\fP|\fBs\fP|\fBt\fP|\fBu\fP|\fBv\fP]] [\fIlimit\fP]
-Handles resource limits for the shell
-and processes created by it,
-as described in
-.IR getrlimit (2).
-Without a
-.I limit
-argument,
-the current settings are printed;
-otherwise, a new limit is set.
-The following options are accepted:
-.RS
-.PD 0
-.TP
-.B \-H
-Sets a hard limit.
-Only the super-user may raise a hard limit.
-.TP
-.B \-S
-Sets a soft limit.
-A soft limit must not exceed the hard limit.
-.IP
-If neither
-.I \-H
-or
-.I \-S
-is given,
-the soft limit is printed,
-or both limits are set, respectively.
-.TP
-.B \-a
-Chooses all limits described.
-.TP
-.B \-c
-The maximum size of a core dump in 512-byte blocks.
-.TP
-.B \-d
-The maximum size of the data segment in kbytes.
-.TP
-.B \-f
-The maximum size of a file in 512-byte blocks.
-This is the default if no limit is explicitly selected.
-.TP
-.B \-l
-The maximum size of locked memory in kbytes.
-.TP
-.B \-m
-The maximum resident set size in kbytes.
-.TP
-.B \-n
-The maximum number of open file descriptors.
-.TP
-.B \-s
-The maximum size of the stack segment in kbytes.
-.TP
-.B \-t
-The maximum processor time in seconds.
-.TP
-.B \-u
-The maximum number of child processes.
-.TP
-.B \-v
-The maximum address space size in kbytes.
-.PD
-.RE
-.TP
-\fBumask \fR[\fB\-S\fR] [\fInnn\fR]
-The user file creation mask is set to
-the octal value
-.I nnn
-(see
-.IR umask (2)).
-Symbolic modes as described in
-.IR chmod (1)
-are also accepted.
-If
-.I nnn
-is omitted, the current value of the mask is printed.
-With the
-.B \-S
-option, the current mask is printed as a symbolic string.
-.TP
-\fBunset\fI variable \fR...
-Unsets each
-.I variable
-named.
-.TP
-\fBwait\fP [\fIn\fP]
-Wait for the specified process and
-report its termination status.
-If
-.I n
-is not given then all currently active child processes are waited for.
-The return code from this command is that of
-the process waited for.
-If
-.I n
-does not refer to a child process of the shell,
-.I wait
-returns immediately with code 0.
-.PD
-.PP
-.SS "Invocation"
-If the first character of argument zero is
-.BR \- ,
-commands are read from
-.B /etc/profile
-and
-.BR \s-1$HOME\s0/.\|profile ,
-if the respective file exists.
-Commands are then read as described below.
-The following flags are interpreted by the shell
-when it is invoked.
-.PD 0
-.TP 11n
-.BI \-c \ string
-If the
-.B \-c
-flag is present then
-commands are read from
-.I string\|.
-.TP 11n
-.B \-s
-If the
-.B \-s
-flag is present or if no
-arguments remain
-then commands are read from the standard input.
-Shell output is written to
-file descriptor 2.
-.TP 11n
-.B \-i
-If the
-.B \-i
-flag is present or
-if the shell input and output are attached to a terminal (as told by
-.IR isatty (3))
-then this shell is
-.I interactive.
-In this case the terminate signal
-SIGTERM (see
-.IR signal (2))
-is ignored (so that `kill 0'
-does not kill an interactive shell) and the interrupt signal
-SIGINT is caught and ignored
-(so that
-.B wait
-is interruptable).
-In all cases SIGQUIT is ignored by the shell.
-.PD
-.PP
-The remaining flags and arguments are described under the
-.B set
-command.
-.SS "Job Control"
-When an interactive shell is invoked as
-.BR jsh ,
-job control is enabled.
-Job control allows to stop and resume processes,
-and to switch between foreground and background jobs.
-A job consists of the commands of a single pipeline.
-Each job is placed in a separate process group;
-a login shell and all jobs created by it form a session.
-Interrupt, quit, and other terminal control characters
-only affect the current foreground process group.
-The foreground job can be stopped pressing the
-suspend key, typically
-.IR ^Z ;
-any job can be stopped by sending the
-.SM STOP
-signal to it.
-Jobs are identified by
-.I "jod ids"
-of the following form:
-.TP
-.BR % " or " %% " or " %+
-The current job.
-.TP
-.B %\-
-The job that was previously the current job.
-.TP
-.BI ? string
-The only job whose name contains
-.IR string .
-.TP
-.BI % number
-The job with the given number.
-.TP
-.I number
-The job with process group id
-.IR number .
-.TP
-.I string
-The only job for which
-.I string
-is a prefix of its name.
-.PP
-The following built-in commands are additionally available
-with job control:
-.TP
-\fBbg\fR [\fIjobid\fP ...]
-Places each
-.I jobid
-in the background.
-The default job id is the current job.
-.TP
-\fBfg\fR [\fIjobid\fP ...]
-Sequentially selects each
-.I jobid
-as the foreground job.
-The default job id is the current job.
-.TP
-\fBjobs\fR [\fB\-p\fR|\fB\-l\fR] [\fIjobid\fP ...] | [\fB\-x\fI command \fR[\fIarguments\fR ...]]
-Prints information about each
-.IR jobid ,
-or executes
-.IR command .
-.RS
-.TP
-.B \-l
-Includes the process group id and the starting directory.
-.TP
-.B \-p
-Includes the process group id.
-.TP
-\fB\-x \fIcommand \fR[\fIarguments\fR ...]
-Executes
-.I command
-with
-.IR arguments ;
-each
-.I argument
-that forms a job id
-is replaced by the process group id
-of the respective job.
-It is an error if a given job does not exist.
-.RE
-.TP
-\fBkill\fR [[\fB\-s\fR \fIsignal\fR | \fB\-\fIsignal\fR] \fIjobid\fR ... | \fB-l \fI[status]\fR
-A special version of the
-.IR kill (1)
-command that recognizes job ids in its arguments.
-.TP
-\fBstop \fIjobid\fR ...
-Stops the given jobs
-(i.\|e. sends a
-.SM STOP
-signal to them).
-.TP
-.B suspend
-Stops the shell itself.
-This is not allowed if the shell is a session leader.
-.TP
-\fBwait \fR[\fIjobid\fR]
-The
-.I wait
-command (see above) recognizes job ids in its arguments.
-.SH FILES
-/etc/profile
-.br
-.RB $HOME/ . \^profile
-.br
-/tmp/sh*
-.br
-/dev/null
-.SH SEE ALSO
-env(1),
-exec(2),
-signal(2)
-.SH DIAGNOSTICS
-Errors detected by the shell, such as syntax errors
-or fatal errors in special commands,
-cause the shell
-to return a non zero exit status.
-If the shell is being used non interactively
-then execution of the shell file is abandoned.
-Otherwise, the shell returns the exit status of
-the last command executed (see also
-.IR exit ).
-.SH NOTES
-For historical reasons,
-.I ^
-is a synonym for
-.I \(or
-as pipeline separator.
-Its use in new applications is discouraged.
-.PP
-If a command other than a simple-command
-(i.\|e. `for ...', `case ...' etc.) is redirected,
-it is executed in a subshell.
-If variable assignments must be visible in the parent shell
-after the input has been redirected, the
-.I exec
-special command can be used:
-.RS
-.sp
-.nf
-exec 5<&0 <input
-while read line
-do
- ...
- variable=value
- ...
-done
-exec <&5 5<&\-
-.fi
-.sp
-.RE
-.PP
-If parameters that have been inherited from the initial environment
-are modified,
-they must be explicitly exported
-to make the change visible to external commands,
-as described under `Environment' above.
-.PP
-The
-.SM $IFS
-parameter is applied to any unquoted word.
-Thus
-.RS
-.sp
-.nf
-IFS=X
-echoXfoo
-.fi
-.sp
-.RE
-executes the `echo' command with the argument `foo'.
-.PP
-The command `set \-\-' without further arguments is a no-op.
-The
-.I shift
-special command can be used to delete all positional parameters.
-.PP
-There is only one namespace for both functions and parameters.
-A function definition will delete a parameter with the same name
-and vice-versa.
-.PP
-Parameter assignments that precede a special command
-affect the shell itself;
-parameter assignments that precede the call of a function are ignored.
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