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today, Andreas Buschka learnt that the Oxford comma is an american thing

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(except for exactly the University of Oxford or to disambiguate)
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tg 2016-09-29 09:04:56 +00:00
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@ -1,4 +1,4 @@
.\" $MirOS: src/bin/mksh/mksh.1,v 1.416 2016/08/24 20:40:00 tg Exp $ .\" $MirOS: src/bin/mksh/mksh.1,v 1.417 2016/09/29 09:04:56 tg Exp $
.\" $OpenBSD: ksh.1,v 1.160 2015/07/04 13:27:04 feinerer Exp $ .\" $OpenBSD: ksh.1,v 1.160 2015/07/04 13:27:04 feinerer Exp $
.\"- .\"-
.\" Copyright © 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, .\" Copyright © 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
@ -76,7 +76,7 @@
.\" with -mandoc, it might implement .Mx itself, but we want to .\" with -mandoc, it might implement .Mx itself, but we want to
.\" use our own definition. And .Dd must come *first*, always. .\" use our own definition. And .Dd must come *first*, always.
.\" .\"
.Dd $Mdocdate: August 24 2016 $ .Dd $Mdocdate: September 29 2016 $
.\" .\"
.\" Check which macro package we use, and do other -mdoc setup. .\" Check which macro package we use, and do other -mdoc setup.
.\" .\"
@ -223,7 +223,7 @@ to a
.Xr tty 4 . .Xr tty 4 .
An interactive shell has job control enabled, ignores the An interactive shell has job control enabled, ignores the
.Dv SIGINT , .Dv SIGINT ,
.Dv SIGQUIT , .Dv SIGQUIT
and and
.Dv SIGTERM .Dv SIGTERM
signals, and prints prompts before reading input (see the signals, and prints prompts before reading input (see the
@ -286,7 +286,7 @@ command is disabled.
.It .It
The The
.Ev SHELL , .Ev SHELL ,
.Ev ENV , .Ev ENV
and and
.Ev PATH .Ev PATH
parameters cannot be changed. parameters cannot be changed.
@ -360,7 +360,7 @@ The exit status of the shell is 127 if the command file specified on the
command line could not be opened, or non-zero if a fatal syntax error command line could not be opened, or non-zero if a fatal syntax error
occurred during the execution of a script. occurred during the execution of a script.
In the absence of fatal errors, In the absence of fatal errors,
the exit status is that of the last command executed, or zero, if no the exit status is that of the last command executed, or zero if no
command is executed. command is executed.
.Ss Startup files .Ss Startup files
For the actual location of these files, see For the actual location of these files, see
@ -383,14 +383,14 @@ The shell begins parsing its input by removing any backslash-newline
combinations, then breaking it into combinations, then breaking it into
.Em words . .Em words .
Words (which are sequences of characters) are delimited by unquoted whitespace Words (which are sequences of characters) are delimited by unquoted whitespace
characters (space, tab, and newline) or meta-characters characters (space, tab and newline) or meta-characters
.Po .Po
.Ql \*(Lt , .Ql \*(Lt ,
.Ql \*(Gt , .Ql \*(Gt ,
.Ql \*(Ba , .Ql \*(Ba ,
.Ql \&; , .Ql \&; ,
.Ql \&( , .Ql \&( ,
.Ql \&) , .Ql \&)
and and
.Ql & .Ql &
.Pc . .Pc .
@ -455,7 +455,7 @@ shell and must be quoted if they are to represent themselves:
.Ql { , .Ql { ,
.Ql } , .Ql } ,
.Ql * , .Ql * ,
.Ql \&? , .Ql \&?
and and
.Ql \&[ . .Ql \&[ .
The first three of these are the above mentioned quoting characters (see The first three of these are the above mentioned quoting characters (see
@ -467,7 +467,7 @@ the
.Ql # .Ql #
up to the nearest newline is ignored; up to the nearest newline is ignored;
.Ql $ .Ql $
is used to introduce parameter, command, and arithmetic substitutions (see is used to introduce parameter, command and arithmetic substitutions (see
.Sx Substitution .Sx Substitution
below); below);
.Ql \` .Ql \`
@ -488,7 +488,7 @@ alternations (see
below); below);
and finally, and finally,
.Ql * , .Ql * ,
.Ql \&? , .Ql \&?
and and
.Ql \&[ .Ql \&[
are used in file name generation (see are used in file name generation (see
@ -504,7 +504,7 @@ such as
.Ic for .Ic for
and and
.Ic if .Ic if
statements, grouping constructs, and function definitions. statements, grouping constructs and function definitions.
.Pp .Pp
A simple-command consists of some combination of parameter assignments A simple-command consists of some combination of parameter assignments
(see (see
@ -512,12 +512,12 @@ A simple-command consists of some combination of parameter assignments
below), below),
input/output redirections (see input/output redirections (see
.Sx Input/output redirections .Sx Input/output redirections
below), below)
and command words; the only restriction is that parameter assignments come and command words; the only restriction is that parameter assignments come
before any command words. before any command words.
The command words, if any, define the command The command words, if any, define the command
that is to be executed and its arguments. that is to be executed and its arguments.
The command may be a shell built-in command, a function, The command may be a shell built-in command, a function
or an external command or an external command
(i.e. a separate executable file that is located using the (i.e. a separate executable file that is located using the
.Ev PATH .Ev PATH
@ -564,7 +564,7 @@ tokens:
.Dq Li && , .Dq Li && ,
.Dq Li \*(Ba\*(Ba , .Dq Li \*(Ba\*(Ba ,
.Dq Li & , .Dq Li & ,
.Dq Li \*(Ba& , .Dq Li \*(Ba&
and and
.Dq Li \&; . .Dq Li \&; .
The first two are for conditional execution: The first two are for conditional execution:
@ -585,7 +585,7 @@ and
.Dq Li \*(Ba\*(Ba .Dq Li \*(Ba\*(Ba
have equal precedence which is higher than that of have equal precedence which is higher than that of
.Dq Li & , .Dq Li & ,
.Dq Li \*(Ba& , .Dq Li \*(Ba&
and and
.Dq Li \&; , .Dq Li \&; ,
which also have equal precedence. which also have equal precedence.
@ -629,7 +629,7 @@ and
.Dq Li \*(Ba\*(Ba .Dq Li \*(Ba\*(Ba
operators, while it need not follow operators, while it need not follow
.Dq Li & , .Dq Li & ,
.Dq Li \*(Ba& , .Dq Li \*(Ba&
or or
.Dq Li \&; . .Dq Li \&; .
The exit status of a list is that of the last command executed, with the The exit status of a list is that of the last command executed, with the
@ -649,7 +649,7 @@ elif for select while }
.Pp .Pp
In the following compound command descriptions, command lists (denoted as In the following compound command descriptions, command lists (denoted as
.Em list ) .Em list )
that are followed by reserved words must end with a semicolon, a newline, or that are followed by reserved words must end with a semicolon, a newline or
a (syntactically correct) reserved word. a (syntactically correct) reserved word.
For example, the following are all valid: For example, the following are all valid:
.Bd -literal -offset indent .Bd -literal -offset indent
@ -706,7 +706,7 @@ are dropped.
Note that any unquoted space before and after a pattern is Note that any unquoted space before and after a pattern is
stripped; any space within a pattern must be quoted. stripped; any space within a pattern must be quoted.
Both the word and the Both the word and the
patterns are subject to parameter, command, and arithmetic substitution, as patterns are subject to parameter, command and arithmetic substitution, as
well as tilde substitution. well as tilde substitution.
.Pp .Pp
For historical reasons, open and close braces may be used instead of For historical reasons, open and close braces may be used instead of
@ -948,7 +948,7 @@ Operators (e.g.\&
.Dq Li \&! ) .Dq Li \&! )
must be unquoted. must be unquoted.
.It .It
Parameter, command, and arithmetic substitutions are performed as expressions Parameter, command and arithmetic substitutions are performed as expressions
are evaluated and lazy expression evaluation is used for the are evaluated and lazy expression evaluation is used for the
.Dq Li && .Dq Li &&
and and
@ -999,14 +999,14 @@ Third, a double quote
.Pq Ql \&" .Pq Ql \&"
quotes all characters, except quotes all characters, except
.Ql $ , .Ql $ ,
.Ql \e , .Ql \e
and and
.Ql \` , .Ql \` ,
up to the next unescaped double quote. up to the next unescaped double quote.
.Ql $ .Ql $
and and
.Ql \` .Ql \`
inside double quotes have their usual meaning (i.e. parameter, arithmetic, inside double quotes have their usual meaning (i.e. parameter, arithmetic
or command substitution) except no field splitting is carried out on the or command substitution) except no field splitting is carried out on the
results of double-quoted substitutions, and the old-style form of command results of double-quoted substitutions, and the old-style form of command
substitution has backslash-quoting for double quotes enabled. substitution has backslash-quoting for double quotes enabled.
@ -1015,7 +1015,7 @@ If a
inside a double-quoted string is followed by inside a double-quoted string is followed by
.Ql \&" , .Ql \&" ,
.Ql $ , .Ql $ ,
.Ql \e , .Ql \e
or or
.Ql \` , .Ql \` ,
only the only the
@ -1052,7 +1052,7 @@ These include
.Dq Li \er , .Dq Li \er ,
.Dq Li \et , .Dq Li \et ,
.Dq Li \eU######## , .Dq Li \eU######## ,
.Dq Li \eu#### , .Dq Li \eu####
and and
.Dq Li \ev . .Dq Li \ev .
For For
@ -1072,7 +1072,7 @@ In the
.Ic print .Ic print
builtin mode, builtin mode,
.Dq Li \e" , .Dq Li \e" ,
.Dq Li \e\*(aq , .Dq Li \e\*(aq
and and
.Dq Li \e? .Dq Li \e?
are explicitly excluded; are explicitly excluded;
@ -1180,14 +1180,14 @@ automatically tracked:
.Xr rm 1 , .Xr rm 1 ,
.Xr sed 1 , .Xr sed 1 ,
.Xr sh 1 , .Xr sh 1 ,
.Xr vi 1 , .Xr vi 1
and and
.Xr who 1 . .Xr who 1 .
.Ss Substitution .Ss Substitution
The first step the shell takes in executing a simple-command is to perform The first step the shell takes in executing a simple-command is to perform
substitutions on the words of the command. substitutions on the words of the command.
There are three kinds of There are three kinds of
substitution: parameter, command, and arithmetic. substitution: parameter, command and arithmetic.
Parameter substitutions, Parameter substitutions,
which are described in detail in the next section, take the form which are described in detail in the next section, take the form
.Pf $ Ns Ar name .Pf $ Ns Ar name
@ -1231,7 +1231,7 @@ parameter.
The The
.Ev IFS .Ev IFS
parameter specifies a list of octets which are used to break a string up parameter specifies a list of octets which are used to break a string up
into several words; any octets from the set space, tab, and newline that into several words; any octets from the set space, tab and newline that
appear in the appear in the
.Ev IFS .Ev IFS
octets are called octets are called
@ -1251,20 +1251,19 @@ whitespace does create an empty field.
Example: If Example: If
.Ev IFS .Ev IFS
is set to is set to
.Dq Li \*(Ltspace\*(Gt: , .Dq Li \*(Ltspace\*(Gt:
and VAR is set to and VAR is set to
.Dq Li \*(Ltspace\*(GtA\*(Ltspace\*(Gt:\*(Ltspace\*(Gt\*(Ltspace\*(GtB::D , .Dq Li \*(Ltspace\*(GtA\*(Ltspace\*(Gt:\*(Ltspace\*(Gt\*(Ltspace\*(GtB::D ,
the substitution for $VAR results in four fields: the substitution for $VAR results in four fields:
.Dq Li A , .Dq Li A ,
.Dq Li B , .Dq Li B ,
.Dq .Dq
(an empty field), (an empty field) and
and
.Dq Li D . .Dq Li D .
Note that if the Note that if the
.Ev IFS .Ev IFS
parameter is set to the empty string, no field splitting is done; parameter is set to the empty string, no field splitting is done;
if it is unset, the default value of space, tab, and newline is used. if it is unset, the default value of space, tab and newline is used.
.Pp .Pp
Also, note that the field splitting applies only to the immediate result of Also, note that the field splitting applies only to the immediate result of
the substitution. the substitution.
@ -1272,14 +1271,14 @@ Using the previous example, the substitution for $VAR:E
results in the fields: results in the fields:
.Dq Li A , .Dq Li A ,
.Dq Li B , .Dq Li B ,
.Dq , .Dq
and and
.Dq Li D:E , .Dq Li D:E ,
not not
.Dq Li A , .Dq Li A ,
.Dq Li B , .Dq Li B ,
.Dq , .Dq ,
.Dq Li D , .Dq Li D
and and
.Dq Li E . .Dq Li E .
This behavior is POSIX compliant, but incompatible with some other shell This behavior is POSIX compliant, but incompatible with some other shell
@ -1307,7 +1306,7 @@ form, a
.Ql \e .Ql \e
followed by any of followed by any of
.Ql $ , .Ql $ ,
.Ql \` , .Ql \`
or or
.Ql \e .Ql \e
is stripped (as is is stripped (as is
@ -1372,7 +1371,7 @@ That is, they are a 32-bit unsigned integer.
.Pp .Pp
Parameter substitutions take the form Parameter substitutions take the form
.Pf $ Ns Ar name , .Pf $ Ns Ar name ,
.Pf ${ Ns Ar name Ns } , .Pf ${ Ns Ar name Ns }
or or
.Sm off .Sm off
.Pf ${ Ar name Oo Ar expr Oc } .Pf ${ Ar name Oo Ar expr Oc }
@ -1396,7 +1395,7 @@ is set, in which case an error occurs.
Parameters can be assigned values in a number of ways. Parameters can be assigned values in a number of ways.
First, the shell implicitly sets some parameters like First, the shell implicitly sets some parameters like
.Dq Li # , .Dq Li # ,
.Dq Li PWD , .Dq Li PWD
and and
.Dq Li $ ; .Dq Li $ ;
this is the only way the special single character parameters are set. this is the only way the special single character parameters are set.
@ -1420,7 +1419,7 @@ is also recognised; the old and new values are immediately concatenated.
The fourth way of setting a parameter is with the The fourth way of setting a parameter is with the
.Ic export , .Ic export ,
.Ic global , .Ic global ,
.Ic readonly , .Ic readonly
and and
.Ic typeset .Ic typeset
commands; see their descriptions in the commands; see their descriptions in the
@ -1432,7 +1431,7 @@ and
.Ic select .Ic select
loops set parameters as well as the loops set parameters as well as the
.Ic getopts , .Ic getopts ,
.Ic read , .Ic read
and and
.Ic set Fl A .Ic set Fl A
commands. commands.
@ -1504,7 +1503,7 @@ it is substituted; otherwise,
is printed on standard error (preceded by is printed on standard error (preceded by
.Ar name : ) .Ar name : )
and an error occurs (normally causing termination of a shell script, function, and an error occurs (normally causing termination of a shell script, function,
or script sourced using the or a script sourced using the
.Dq Li \&. .Dq Li \&.
built-in). built-in).
If If
@ -1530,7 +1529,7 @@ can be omitted, in which case the conditions only depend on
being set (as opposed to set and not empty). being set (as opposed to set and not empty).
If If
.Ar word .Ar word
is needed, parameter, command, arithmetic, and tilde substitution are performed is needed, parameter, command, arithmetic and tilde substitution are performed
on it; if on it; if
.Ar word .Ar word
is not needed, it is not evaluated. is not needed, it is not evaluated.
@ -1547,7 +1546,7 @@ The number of positional parameters if
.Ar name .Ar name
is is
.Dq Li * , .Dq Li * ,
.Dq Li @ , .Dq Li @
or not specified; otherwise the length or not specified; otherwise the length
.Pq in characters .Pq in characters
of the string value of parameter of the string value of parameter
@ -1752,7 +1751,7 @@ If no background processes have been started, the parameter is not set.
.It Ev \&# .It Ev \&#
The number of positional parameters ($1, $2, etc.). The number of positional parameters ($1, $2, etc.).
.It Ev \&$ .It Ev \&$
The PID of the shell, or the PID of the original shell if it is a subshell. The PID of the shell or, if it is a subshell, the PID of the original shell.
Do Do
.Em NOT .Em NOT
use this mechanism for generating temporary file names; see use this mechanism for generating temporary file names; see
@ -1844,9 +1843,9 @@ value as reported by
.Xr stty 1 .Xr stty 1
is non-zero and sane enough (minimum is 12x3); similar for is non-zero and sane enough (minimum is 12x3); similar for
.Ev LINES . .Ev LINES .
This parameter is used by the interactive line editing modes, and by the This parameter is used by the interactive line editing modes and by the
.Ic select , .Ic select ,
.Ic set Fl o , .Ic set Fl o
and and
.Ic kill Fl l .Ic kill Fl l
commands to format information columns. commands to format information columns.
@ -1920,7 +1919,7 @@ below).
.It Ev IFS .It Ev IFS
Internal field separator, used during substitution and by the Internal field separator, used during substitution and by the
.Ic read .Ic read
command, to split values into distinct arguments; normally set to space, tab, command, to split values into distinct arguments; normally set to space, tab
and newline. and newline.
See See
.Sx Substitution .Sx Substitution
@ -2018,7 +2017,7 @@ See
The previous working directory. The previous working directory.
Unset if Unset if
.Ic cd .Ic cd
has not successfully changed directories since the shell started, or if the has not successfully changed directories since the shell started or if the
shell doesn't know where it is. shell doesn't know where it is.
.It Ev OPTARG .It Ev OPTARG
When using When using
@ -2048,7 +2047,7 @@ one by one, of the last pipeline run in the foreground.
The process ID of the shell's parent. The process ID of the shell's parent.
.It Ev PS1 .It Ev PS1
The primary prompt for interactive shells. The primary prompt for interactive shells.
Parameter, command, and arithmetic Parameter, command and arithmetic
substitutions are performed, and substitutions are performed, and
.Ql \&! .Ql \&!
is replaced with the current command number (see the is replaced with the current command number (see the
@ -2108,7 +2107,7 @@ if you did not have any non-printing characters.
Since Backslashes and other special characters may be Since Backslashes and other special characters may be
interpreted by the shell, to set interpreted by the shell, to set
.Ev PS1 .Ev PS1
either escape the backslash itself, either escape the backslash itself
or use double quotes. or use double quotes.
The latter is more practical. The latter is more practical.
This is a more complex example, This is a more complex example,
@ -2144,7 +2143,7 @@ The default is
Used to prefix commands that are printed during execution tracing (see the Used to prefix commands that are printed during execution tracing (see the
.Ic set Fl x .Ic set Fl x
command below). command below).
Parameter, command, and arithmetic substitutions are performed Parameter, command and arithmetic substitutions are performed
before it is printed. before it is printed.
The default is The default is
.Dq Li +\ \& . .Dq Li +\ \& .
@ -2179,7 +2178,7 @@ If the time is exceeded, the shell exits.
.It Ev TMPDIR .It Ev TMPDIR
The directory temporary shell files are created in. The directory temporary shell files are created in.
If this parameter is not If this parameter is not
set, or does not contain the absolute path of a writable directory, temporary set or does not contain the absolute path of a writable directory, temporary
files are created in files are created in
.Pa /tmp . .Pa /tmp .
.It Ev USER_ID .It Ev USER_ID
@ -2193,12 +2192,12 @@ The characters following the tilde, up to the first
.Ql / , .Ql / ,
if any, are assumed to be a login name. if any, are assumed to be a login name.
If the login name is empty, If the login name is empty,
.Ql + , .Ql +
or or
.Ql \- , .Ql \- ,
the simplified value of the the simplified value of the
.Ev HOME , .Ev HOME ,
.Ev PWD , .Ev PWD
or or
.Ev OLDPWD .Ev OLDPWD
parameter is substituted, respectively. parameter is substituted, respectively.
@ -2215,7 +2214,7 @@ in the arguments of
.Ic alias , .Ic alias ,
.Ic export , .Ic export ,
.Ic global , .Ic global ,
.Ic readonly , .Ic readonly
and and
.Ic typeset ) , .Ic typeset ) ,
tilde expansion is done after any assignment tilde expansion is done after any assignment
@ -2227,7 +2226,7 @@ login names are also delimited by colons.
The home directory of previously expanded login names are cached and re-used. The home directory of previously expanded login names are cached and re-used.
The The
.Ic alias Fl d .Ic alias Fl d
command may be used to list, change, and add to this cache (e.g.\& command may be used to list, change and add to this cache (e.g.\&
.Ic alias \-d fac=/usr/local/facilities; cd \*(TIfac/bin ) . .Ic alias \-d fac=/usr/local/facilities; cd \*(TIfac/bin ) .
.Ss Brace expansion (alternation) .Ss Brace expansion (alternation)
Brace expressions take the following form: Brace expressions take the following form:
@ -2244,7 +2243,7 @@ The expressions are expanded to
.Ar N .Ar N
words, each of which is the concatenation of words, each of which is the concatenation of
.Ar prefix , .Ar prefix ,
.Ar str Ns i , .Ar str Ns i
and and
.Ar suffix .Ar suffix
(e.g.\& (e.g.\&
@ -2252,7 +2251,7 @@ and
expands to four words: expands to four words:
.Dq Li ace , .Dq Li ace ,
.Dq Li abXe , .Dq Li abXe ,
.Dq Li abYe , .Dq Li abYe
and and
.Dq Li ade ) . .Dq Li ade ) .
As noted in the example, brace expressions can be nested and the resulting As noted in the example, brace expressions can be nested and the resulting
@ -2271,7 +2270,7 @@ A file name pattern is a word containing one or more unquoted
.Ql \&? , .Ql \&? ,
.Ql * , .Ql * ,
.Ql + , .Ql + ,
.Ql @ , .Ql @
or or
.Ql \&! .Ql \&!
characters or characters or
@ -2343,7 +2342,7 @@ Example: The pattern
.Ic ?(foo\*(Babar) .Ic ?(foo\*(Babar)
only matches the strings only matches the strings
.Dq , .Dq ,
.Dq Li foo , .Dq Li foo
and and
.Dq Li bar . .Dq Li bar .
.Sm off .Sm off
@ -2387,7 +2386,7 @@ but
.At .At
.Nm ksh , .Nm ksh ,
Bourne Bourne
.Nm sh , .Nm sh
and GNU and GNU
.Nm bash .Nm bash
do. do.
@ -2409,8 +2408,8 @@ option is set, any directories that result from file name generation are marked
with a trailing with a trailing
.Ql / . .Ql / .
.Ss Input/output redirection .Ss Input/output redirection
When a command is executed, its standard input, standard output, and standard When a command is executed, its standard input, standard output and standard
error (file descriptors 0, 1, and 2, respectively) are normally inherited from error (file descriptors 0, 1 and 2, respectively) are normally inherited from
the shell. the shell.
Three exceptions to this are commands in pipelines, for which Three exceptions to this are commands in pipelines, for which
standard input and/or standard output are those set up by the pipeline, standard input and/or standard output are those set up by the pipeline,
@ -2471,13 +2470,13 @@ If
.Ar marker .Ar marker
contains no quoted characters, the contents of the temporary file are processed contains no quoted characters, the contents of the temporary file are processed
as if enclosed in double quotes each time the command is executed, so as if enclosed in double quotes each time the command is executed, so
parameter, command, and arithmetic substitutions are performed, along with parameter, command and arithmetic substitutions are performed, along with
backslash backslash
.Pq Ql \e .Pq Ql \e
escapes for escapes for
.Ql $ , .Ql $ ,
.Ql \` , .Ql \` ,
.Ql \e , .Ql \e
and and
.Dq Li \enewline , .Dq Li \enewline ,
but not for but not for
@ -2547,7 +2546,7 @@ but a syntax error in GNU
.Xc .Xc
Same as Same as
.Ic \*(Gt\*(Ba Ns Ar file , .Ic \*(Gt\*(Ba Ns Ar file ,
.Ic \*(Gt\*(Gt Ns Ar file , .Ic \*(Gt\*(Gt Ns Ar file
or or
.Ic \*(Gt& Ns Ar fd , .Ic \*(Gt& Ns Ar fd ,
followed by followed by
@ -2562,11 +2561,11 @@ In any of the above redirections, the file descriptor that is redirected
(i.e. standard input or standard output) (i.e. standard input or standard output)
can be explicitly given by preceding the can be explicitly given by preceding the
redirection with a single digit. redirection with a single digit.
Parameter, command, and arithmetic Parameter, command and arithmetic
substitutions, tilde substitutions, and (if the shell is interactive) substitutions, tilde substitutions, and, if the shell is interactive,
file name generation are all performed on the file name generation are all performed on the
.Ar file , .Ar file ,
.Ar marker , .Ar marker
and and
.Ar fd .Ar fd
arguments of redirections. arguments of redirections.
@ -2613,7 +2612,7 @@ character, in which case they use
.Vt mksh_uari_t .Vt mksh_uari_t
.Po a 32-bit unsigned integer Pc . .Po a 32-bit unsigned integer Pc .
.Pp .Pp
Expressions may contain alpha-numeric parameter identifiers, array references, Expressions may contain alpha-numeric parameter identifiers, array references
and integer constants and may be combined with the following C operators and integer constants and may be combined with the following C operators
(listed and grouped in increasing order of precedence): (listed and grouped in increasing order of precedence):
.Pp .Pp
@ -2783,7 +2782,7 @@ Rotate left (right); the result is similar to shift,
except that the bits shifted out at one end are shifted in except that the bits shifted out at one end are shifted in
at the other end, instead of zero or sign bits. at the other end, instead of zero or sign bits.
.It + \- * / .It + \- * /
Addition, subtraction, multiplication, and division. Addition, subtraction, multiplication and division.
.It % .It %
Remainder; the result is the symmetric remainder of the division of the left Remainder; the result is the symmetric remainder of the division of the left
argument by the right. argument by the right.
@ -2992,9 +2991,9 @@ The EXIT trap, if set in a function, will be executed after the function
returns. returns.
.El .El
.Ss Command execution .Ss Command execution
After evaluation of command-line arguments, redirections, and parameter After evaluation of command-line arguments, redirections and parameter
assignments, the type of command is determined: a special built-in command, assignments, the type of command is determined: a special built-in command,
a function, a normal builtin, or the name of a file to execute found using the a function, a normal builtin or the name of a file to execute found using the
.Ev PATH .Ev PATH
parameter. parameter.
The checks are made in the above order. The checks are made in the above order.
@ -3202,7 +3201,7 @@ Exit the
inner-most inner-most
.Ic for , .Ic for ,
.Ic select , .Ic select ,
.Ic until , .Ic until
or or
.Ic while .Ic while
loop. loop.
@ -3304,7 +3303,7 @@ parameters are updated to reflect the current and old working directory,
respectively. respectively.
If the If the
.Fl e .Fl e
option is set for physical filesystem traversal, and option is set for physical filesystem traversal and
.Ev PWD .Ev PWD
could not be set, the exit code is 1; greater than 1 if an could not be set, the exit code is 1; greater than 1 if an
error occurred, 0 otherwise. error occurred, 0 otherwise.
@ -3381,7 +3380,7 @@ Jumps to the beginning of the
inner-most inner-most
.Ic for , .Ic for ,
.Ic select , .Ic select ,
.Ic until , .Ic until
or or
.Ic while .Ic while
loop. loop.
@ -3517,7 +3516,7 @@ Without
.Fl l , .Fl l ,
the selected commands are edited by the editor specified with the the selected commands are edited by the editor specified with the
.Fl e .Fl e
option, or if no option or, if no
.Fl e .Fl e
is specified, the editor specified by the is specified, the editor specified by the
.Ev FCEDIT .Ev FCEDIT
@ -3628,9 +3627,9 @@ invoked).
.Pp .Pp
Warning: Changing the value of the shell parameter Warning: Changing the value of the shell parameter
.Ev OPTIND .Ev OPTIND
to a value other than 1, or parsing different sets of arguments without to a value other than 1 or parsing different sets of arguments without
resetting resetting
.Ev OPTIND , .Ev OPTIND
may lead to unexpected results. may lead to unexpected results.
.Pp .Pp
.It global Ar ... .It global Ar ...
@ -3682,7 +3681,7 @@ and the displayed job.
.No { Ar job \*(Ba pid \*(Ba pgrp No } .No { Ar job \*(Ba pid \*(Ba pgrp No }
.Ar ... .Ar ...
.Xc .Xc
Send the specified signal to the specified jobs, process IDs, or process Send the specified signal to the specified jobs, process IDs or process
groups. groups.
If no signal is specified, the If no signal is specified, the
.Dv TERM .Dv TERM
@ -3700,8 +3699,8 @@ below for the format of
.Xc .Xc
Print the signal name corresponding to Print the signal name corresponding to
.Ar exit-status . .Ar exit-status .
If no arguments are specified, a list of all the signals, their numbers, and If no arguments are specified, a list of all the signals with their numbers
a short description of them are printed. and a short description of each are printed.
.Pp .Pp
.It Ic let Op Ar expression ... .It Ic let Op Ar expression ...
Each expression is evaluated (see Each expression is evaluated (see
@ -3738,7 +3737,7 @@ The file type may be
.Cm b .Cm b
(block type device), (block type device),
.Cm c .Cm c
(character type device), (character type device)
or or
.Cm p .Cm p
.Pq named pipe , Tn FIFO . .Pq named pipe , Tn FIFO .
@ -4140,7 +4139,7 @@ This does not apply to commands whose exit status is
explicitly tested by a shell construct such as explicitly tested by a shell construct such as
.Ic if , .Ic if ,
.Ic until , .Ic until ,
.Ic while , .Ic while
or or
.Ic \&! .Ic \&!
statements. statements.
@ -4208,7 +4207,7 @@ and optionally
.Fn nl_langinfo CODESET , .Fn nl_langinfo CODESET ,
or the or the
.Ev LC_ALL , .Ev LC_ALL ,
.Ev LC_CTYPE , .Ev LC_CTYPE
or or
.Ev LANG .Ev LANG
environment variables, environment variables,
@ -4232,7 +4231,7 @@ or
.Dq Li $* , .Dq Li $* ,
is treated as an error, unless one of the is treated as an error, unless one of the
.Ql \- , .Ql \- ,
.Ql + , .Ql +
or or
.Ql = .Ql =
modifiers is used. modifiers is used.
@ -4645,7 +4644,7 @@ which fails if parameter
.Dq foo .Dq foo
is empty or unset, if it has embedded spaces (i.e.\& is empty or unset, if it has embedded spaces (i.e.\&
.Ev IFS .Ev IFS
octets), or if it is a unary operator like octets) or if it is a unary operator like
.Dq Li \&! .Dq Li \&!
or or
.Dq Li \-n . .Dq Li \-n .
@ -4737,7 +4736,7 @@ is either an empty string, indicating the signals are to be ignored, a dash
indicating that the default action is to be taken for the signals indicating that the default action is to be taken for the signals
.Pq see Xr signal 3 , .Pq see Xr signal 3 ,
or a string containing shell commands to be executed at the first opportunity or a string containing shell commands to be executed at the first opportunity
(i.e. when the current command completes, or before printing the next (i.e. when the current command completes or before printing the next
.Ev PS1 .Ev PS1
prompt) after receipt of one of the signals. prompt) after receipt of one of the signals.
.Ar signal .Ar signal
@ -4988,7 +4987,7 @@ If any of the
.Fl l , .Fl l ,
.Fl R , .Fl R ,
.Fl U , .Fl U ,
.Fl u , .Fl u
or or
.Fl Z .Fl Z
options are changed, all others from this set are cleared, options are changed, all others from this set are cleared,
@ -5118,7 +5117,7 @@ is concerned, a block is 512 bytes.
.Op Fl S .Op Fl S
.Op Ar mask .Op Ar mask
.Xc .Xc
Display or set the file permission creation mask, or umask (see Display or set the file permission creation mask or umask (see
.Xr umask 2 ) . .Xr umask 2 ) .
If the If the
.Fl S .Fl S
@ -5131,7 +5130,7 @@ When used, they describe what permissions may be made available (as opposed to
octal masks in which a set bit means the corresponding bit is to be cleared). octal masks in which a set bit means the corresponding bit is to be cleared).
For example, For example,
.Dq Li ug=rwx,o= .Dq Li ug=rwx,o=
sets the mask so files will not be readable, writable, or executable by sets the mask so files will not be readable, writable or executable by
.Dq others , .Dq others ,
and is equivalent (on most systems) to the octal mask and is equivalent (on most systems) to the octal mask
.Dq Li 007 . .Dq Li 007 .
@ -5178,7 +5177,7 @@ The exit status of
is that of the last specified job; if the last job is killed by a signal, the is that of the last specified job; if the last job is killed by a signal, the
exit status is 128 + the number of the signal (see exit status is 128 + the number of the signal (see
.Ic kill Fl l Ar exit-status .Ic kill Fl l Ar exit-status
above); if the last specified job can't be found (because it never existed, or above); if the last specified job can't be found (because it never existed or
had already finished), the exit status of had already finished), the exit status of
.Ic wait .Ic wait
is 127. is 127.
@ -5187,9 +5186,9 @@ See
below for the format of below for the format of
.Ar job . .Ar job .
.Ic wait .Ic wait
will return if a signal for which a trap has been set is received, or if a will return if a signal for which a trap has been set is received or if a
.Dv SIGHUP , .Dv SIGHUP ,
.Dv SIGINT , .Dv SIGINT
or or
.Dv SIGQUIT .Dv SIGQUIT
signal is received. signal is received.
@ -5245,7 +5244,7 @@ commands, and the state of the terminal is saved or restored when a foreground
job is stopped or restarted, respectively. job is stopped or restarted, respectively.
.Pp .Pp
Note that only commands that create processes (e.g. asynchronous commands, Note that only commands that create processes (e.g. asynchronous commands,
subshell commands, and non-built-in, non-function commands) can be stopped; subshell commands and non-built-in, non-function commands) can be stopped;
commands like commands like
.Ic read .Ic read
cannot be. cannot be.
@ -5259,7 +5258,7 @@ A job may be referred to in the
.Ic bg , .Ic bg ,
.Ic fg , .Ic fg ,
.Ic jobs , .Ic jobs ,
.Ic kill , .Ic kill
and and
.Ic wait .Ic wait
commands either by the process ID of the last process in the command pipeline commands either by the process ID of the last process in the command pipeline
@ -5270,7 +5269,7 @@ parameter) or by prefixing the job number with a percent sign
Other percent sequences can also be used to refer to jobs: Other percent sequences can also be used to refer to jobs:
.Bl -tag -width "%+ x %% x %XX" .Bl -tag -width "%+ x %% x %XX"
.It %+ \*(Ba %% \*(Ba % .It %+ \*(Ba %% \*(Ba %
The most recently stopped job, or, if there are no stopped jobs, the oldest The most recently stopped job or, if there are no stopped jobs, the oldest
running job. running job.
.It %\- .It %\-
The job that would be the The job that would be the
@ -5376,7 +5375,7 @@ refer to the
manual page for details. manual page for details.
Most other historic, Most other historic,
.At .At
.Nm ksh Ns -compatible , .Nm ksh Ns -compatible
or opinionated differences can be disabled by using this mode; these are: or opinionated differences can be disabled by using this mode; these are:
.Bl -bullet .Bl -bullet
.It .It
@ -5452,7 +5451,7 @@ The shell supports three modes of reading command lines from a
.Xr tty 4 .Xr tty 4
in an interactive session, controlled by the in an interactive session, controlled by the
.Ic emacs , .Ic emacs ,
.Ic gmacs , .Ic gmacs
and and
.Ic vi .Ic vi
options (at most one of these can be set at once). options (at most one of these can be set at once).
@ -5480,7 +5479,7 @@ In these editing modes, if a line is longer than the screen width (see the
parameter), parameter),
a a
.Ql \*(Gt , .Ql \*(Gt ,
.Ql + , .Ql +
or or
.Ql \*(Lt .Ql \*(Lt
character is displayed in the last column indicating that there are more character is displayed in the last column indicating that there are more
@ -5489,7 +5488,7 @@ respectively.
The line is scrolled horizontally as necessary. The line is scrolled horizontally as necessary.
.Pp .Pp
Completed lines are pushed into the history, unless they begin with an Completed lines are pushed into the history, unless they begin with an
IFS octet or IFS white space, or are the same as the previous line. IFS octet or IFS white space or are the same as the previous line.
.Ss Emacs editing mode .Ss Emacs editing mode
When the When the
.Ic emacs .Ic emacs
@ -5559,7 +5558,7 @@ characters.
.Xc .Xc
Moves the cursor backward to the beginning of the word; words consist of Moves the cursor backward to the beginning of the word; words consist of
alphanumerics, underscore alphanumerics, underscore
.Pq Ql _ , .Pq Ql _
and dollar sign and dollar sign
.Pq Ql $ .Pq Ql $
characters. characters.
@ -5605,7 +5604,7 @@ partial word up to the cursor as its prefix, as in the
.Ic complete .Ic complete
command described above. command described above.
.It complete\-list: \*(haI, \*(ha[= .It complete\-list: \*(haI, \*(ha[=
Complete as much as is possible of the current word, Complete as much as is possible of the current word
and list the possible completions for it. and list the possible completions for it.
If only one completion is possible, If only one completion is possible,
match as in the match as in the
@ -5780,7 +5779,7 @@ Introduces a multi-character command sequence.
.Op Ar n .Op Ar n
.No \*(ha[. , \*(ha[_ .No \*(ha[. , \*(ha[_
.Xc .Xc
The last word, or, if given, the The last word or, if given, the
.Ar n Ns th .Ar n Ns th
word (zero-based) of the previous (on repeated execution, second-last, word (zero-based) of the previous (on repeated execution, second-last,
third-last, etc.) command is inserted at the cursor. third-last, etc.) command is inserted at the cursor.
@ -5846,7 +5845,7 @@ or
.It set\-mark\-command: \*(ha[ Ns Aq space .It set\-mark\-command: \*(ha[ Ns Aq space
Set the mark at the cursor position. Set the mark at the cursor position.
.It transpose\-chars: \*(haT .It transpose\-chars: \*(haT
If at the end of line, or if the If at the end of line or, if the
.Ic gmacs .Ic gmacs
option is set, this exchanges the two previous characters; otherwise, it option is set, this exchanges the two previous characters; otherwise, it
exchanges the previous and current characters and moves the cursor one exchanges the previous and current characters and moves the cursor one
@ -5897,7 +5896,7 @@ editor with the following exceptions:
You start out in insert mode. You start out in insert mode.
.It .It
There are file name and command completion commands: There are file name and command completion commands:
=, \e, *, \*(haX, \*(haE, \*(haF, and, optionally, =, \e, *, \*(haX, \*(haE, \*(haF and, optionally,
.Aq tab .Aq tab
and and
.Aq esc . .Aq esc .
@ -5942,7 +5941,7 @@ settings
(see (see
.Xr stty 1 ) .Xr stty 1 )
and have their usual meaning (normal values are in parentheses): kill (\*(haU), and have their usual meaning (normal values are in parentheses): kill (\*(haU),
erase (\*(ha?), werase (\*(haW), eof (\*(haD), intr (\*(haC), and quit (\*(ha\e). erase (\*(ha?), werase (\*(haW), eof (\*(haD), intr (\*(haC) and quit (\*(ha\e).
In addition to In addition to
the above, the following characters are also treated specially in insert mode: the above, the following characters are also treated specially in insert mode:
.Bl -tag -width XJXXXXM .Bl -tag -width XJXXXXM
@ -5957,7 +5956,7 @@ is undone.
Erases previous character. Erases previous character.
.It \*(haJ \*(Ba \*(haM .It \*(haJ \*(Ba \*(haM
End of line. End of line.
The current line is read, parsed, and executed by the shell. The current line is read, parsed and executed by the shell.
.It \*(haV .It \*(haV
Literal next. Literal next.
The next character typed is not treated specially (can be used The next character typed is not treated specially (can be used
@ -5990,8 +5989,8 @@ refers to the position between the cursor and the character preceding the
cursor. cursor.
A A
.Dq word .Dq word
is a sequence of letters, digits, and underscore characters or a sequence of is a sequence of letters, digits and underscore characters or a sequence of
non-letter, non-digit, non-underscore, and non-whitespace characters (e.g.\& non-letter, non-digit, non-underscore and non-whitespace characters (e.g.\&
.Dq Li ab2*&\*(ha .Dq Li ab2*&\*(ha
contains two words) and a contains two words) and a
.Dq big-word .Dq big-word
@ -6050,13 +6049,13 @@ or follows one of the characters
.Ql \&; , .Ql \&; ,
.Ql \*(Ba , .Ql \*(Ba ,
.Ql & , .Ql & ,
.Ql \&( , .Ql \&(
or or
.Ql \&) , .Ql \&)
and does not contain a slash and does not contain a slash
.Pq Ql / , .Pq Ql / ,
then command expansion is done; otherwise file name expansion is done. then command expansion is done; otherwise file name expansion is done.
Command expansion will match the big-word against all aliases, functions, and Command expansion will match the big-word against all aliases, functions and
built-in commands as well as any executable files found by searching the built-in commands as well as any executable files found by searching the
directories in the directories in the
.Ev PATH .Ev PATH
@ -6169,8 +6168,8 @@ Move forward
big-words. big-words.
.It % .It %
Find match. Find match.
The editor looks forward for the nearest parenthesis, bracket, or The editor looks forward for the nearest parenthesis, bracket or
brace and then moves the cursor to the matching parenthesis, bracket, or brace. brace and then moves the cursor to the matching parenthesis, bracket or brace.
.It Xo .It Xo
.Oo Ar n Oc Ns f Ns Ar c .Oo Ar n Oc Ns f Ns Ar c
.Xc .Xc
@ -6203,7 +6202,7 @@ occurrence of the character
.Oo Ar n Oc Ns \&; .Oo Ar n Oc Ns \&;
.Xc .Xc
Repeats the last Repeats the last
.Ic f , F , t , .Ic f , F , t
or or
.Ic T .Ic T
command. command.
@ -6211,7 +6210,7 @@ command.
.Oo Ar n Oc Ns \&, .Oo Ar n Oc Ns \&,
.Xc .Xc
Repeats the last Repeats the last
.Ic f , F , t , .Ic f , F , t
or or
.Ic T .Ic T
command, but moves in the opposite direction. command, but moves in the opposite direction.
@ -6424,7 +6423,7 @@ except the buffer is pasted at the current position.
Miscellaneous vi commands Miscellaneous vi commands
.Bl -tag -width Ds .Bl -tag -width Ds
.It \*(haJ and \*(haM .It \*(haJ and \*(haM
The current line is read, parsed, and executed by the shell. The current line is read, parsed and executed by the shell.
.It \*(haL and \*(haR .It \*(haL and \*(haR
Redraw the current line. Redraw the current line.
.It Xo .It Xo
@ -6437,7 +6436,7 @@ times.
Undo the last edit command. Undo the last edit command.
.It U .It U
Undo all changes that have been made to the current line. Undo all changes that have been made to the current line.
.It PC Home, End, Del, and cursor keys .It PC Home, End, Del and cursor keys
They move as expected, both in insert and command mode. They move as expected, both in insert and command mode.
.It Ar intr No and Ar quit .It Ar intr No and Ar quit
The interrupt and quit terminal characters cause the current line to be The interrupt and quit terminal characters cause the current line to be
@ -6578,7 +6577,7 @@ and parts of the BRL shell by
.An Doug Kingston , .An Doug Kingston ,
.An Ron Natalie , .An Ron Natalie ,
.An Arnold Robbins , .An Arnold Robbins ,
.An Lou Salkind , .An Lou Salkind
and others. and others.
The first release of The first release of
.Nm pdksh .Nm pdksh
@ -6586,12 +6585,12 @@ was created by
.An Eric Gisin , .An Eric Gisin ,
and it was subsequently maintained by and it was subsequently maintained by
.An John R. MacMillan , .An John R. MacMillan ,
.An Simon J. Gerraty , .An Simon J. Gerraty
and and
.An Michael Rendell . .An Michael Rendell .
The effort of several projects, such as Debian and OpenBSD, and other The effort of several projects, such as Debian and OpenBSD, and other
contributors including our users, to improve the shell is appreciated. contributors including our users, to improve the shell is appreciated.
See the documentation, CVS, and web site for details. See the documentation, web site and CVS for details.
.Pp .Pp
The BSD daemon is Copyright \(co Marshall Kirk McKusick. The BSD daemon is Copyright \(co Marshall Kirk McKusick.
The complete legalese is at: The complete legalese is at: