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diff --git a/static/unix-v10/man1/osh.1 b/static/unix-v10/man1/osh.1 new file mode 100644 index 00000000..3202dfb1 --- /dev/null +++ b/static/unix-v10/man1/osh.1 @@ -0,0 +1,1151 @@ +.if t .ds ' \h@.05m@\s+4\v@.333m@\'\v@-.333m@\s-4\h@.05m@ +.if n .ds ' ' +.if t .ds ` \h@.05m@\s+4\v@.333m@\`\v@-.333m@\s-4\h@.05m@ +.if n .ds ` ` +.ds OK [\| +.ds CK \|] +.TH SH 1 +.SH NAME +sh \- shell, the standard command programming language +.SH SYNOPSIS +.B sh +[ +.B \-ceiknrstuvx +] [ args ] +.SH DESCRIPTION +.I Sh\^ +is a command programming language +that executes commands read from a terminal +or a file. +See +.I Invocation\^ +below +for the meaning of arguments to the shell. +.SS Commands. +A +.I simple-command\^ +is a sequence of non-blank +.I words\^ +separated by +.I blanks\^ +(a +.I blank\^ +is a +tab +or a +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 (octal) 200+\f2status\^\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 +.BR \(bv . +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. +.PP +A +.I list\^ +is a sequence of one or more +pipelines +separated by +.BR ; , +.BR & , +.BR && , +or +.BR \(bv\|\(bv , +and optionally terminated by +.B ; +or +.BR & . +Of these four symbols, +.B ; +and +.B & +have equal precedence, +which is lower than that of +.B && +and +.BR \(bv\|\(bv . +The symbols +.B && +and +.B \(bv\|\(bv +also have equal precedence. +A semicolon +.RB ( ; ) +causes sequential execution of the preceding pipeline; an ampersand +.RB ( & ) +causes asynchronous execution of the preceding pipeline (i.e., the shell does +.I not\^ +wait for that pipeline to finish). +The symbol +.B && +.RB (\| \(bv\|\(bv \^) +causes the +.I list\^ +following it to be executed only if the preceding +pipeline +returns a zero (non-zero) exit status. +An arbitrary number of new-lines may appear in a +.IR list , +instead of semicolons, +to delimit commands. +.PP +A +.I 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. +.PP +.PD 0 +.TP +\f3for\fP \f2name\^\fP \*(OK \f3in\fP \f2word\^\fP .\|.\|. \*(CK \f3do\fP \f2list\^\fP \f3done\fP +Each time a +.B for +command is executed, +.I name\^ +is set to the next +.I word\^ +taken from the +.B in +.I word\^ +list. +If +.BI in " word\^" +\&.\|.\|. +is omitted, then +the +.B for +command executes the \f3do\fP \f2list\^\fP once for each positional parameter +that is set +(see +.I "Parameter Substitution\^" +below). +Execution ends when there are no more words in the list. +.TP +\f3case\fP \f2word\^\fP \f3in\fP \*(OK \f2pattern\^\fP \*(OK \(bv \ +\f2pattern\^\fP \*(CK .\|.\|. \f3)\fP \f2list\^\fP \f3;;\fP \*(CK .\|.\|. \f3esac\fP +A +.B case +command executes the +.I list\^ +associated with the first +.I pattern\^ +that matches +.IR word . +The form of the patterns is +the same as that used for +file-name generation (see +.I "File Name Generation\^" +below). +.TP +\f3if\fP \f2list\^\fP \f3then\fP \f2list\^\fP \*(OK \ +\f3elif\fP \f2list\^\fP \f3then\fP \f2list\^\fP \*(CK .\|.\|. \ +\*(OK \f3else\fP \f2list\^\fP \*(CK \f3f\&i\fP +The +.I list\^ +following \f3if\fP is executed and, +if it +returns a zero exit status, the +.I list\^ +following +the first +.B then +is executed. +Otherwise, the +.I list\^ +following \f3elif\fP +is executed and, if its value is zero, +the +.I list\^ +following +the next +.B then +is executed. +Failing that, the +.B else +.I list\^ +is executed. +If no +.B else +.I list\^ +or +.B then +.I list\^ +is executed, then the +.B if +command returns a zero exit status. +.TP +\f3while\fP \f2list\^\fP \f3do\fP \f2list\^\fP \f3done\fP +A +.B while +command repeatedly executes the +.B while +.I list\^ +and, if the exit status of the last command in the list is zero, executes +the +.B do +.IR list ; +otherwise the loop terminates. +If no commands in the +.B do +.I list\^ +are executed, then the +.B while +command returns a zero exit status; +.B until +may be used in place of +.B while +to negate +the loop termination test. +.TP +\f3(\fP\f2list\^\fP\f3)\fP +.br +Execute +.I list\^ +in a sub-shell. +.TP +\f3{\fP\f2list\^\fP\f3;}\fP +.br +.I list\^ +is simply executed. +.PD +.PP +The following words +are only recognized as the first word of a command +and when not quoted: +.if t .RS +.PP +.B +.if n if then else elif fi case esac for while until do done { } +.if t if then else elif f\&i case esac for while until do done { } +.if t .RE +.SS Comments. +A word beginning with +.B # +causes that word and all the following characters up to a new-line +to be ignored. +.SS Command Substitution. +The standard output from a command enclosed in +a pair of grave accents (\^\f3\*`\^\*`\fP\^) may be used as part or all +of a word; +trailing new-lines are removed. +.SS Parameter Substitution. +The character +.B $ +is used to introduce substitutable +.IR parameters . +Positional parameters may be assigned values by +.BR set . +Variables may be set by writing: +.RS +.PP +.IB name = value\^ +\*(OK +.IB name = value\^ +\*(CK .\|.\|. +.RE +.PP +Pattern-matching is not performed on +.IR value . +.PP +.PD 0 +.TP +\f3${\fP\f2parameter\^\fP\f3}\fP +A +.I parameter\^ +is a sequence of letters, digits, or underscores (a +.IR name ), +a digit, +or any of the characters +.BR \(** , +.BR @ , +.BR # , +.BR ? , +.BR \- , +.BR $ , +and +.BR !\\^ . +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. +A +.I name\^ +must begin with a letter or underscore. +If +.I parameter\^ +is a digit then it is a positional parameter. +If +.I parameter\^ +is +.B \(** +or +.BR @ , +then all the positional +parameters, starting with +.BR $1 , +are substituted +(separated by spaces). +Parameter +.B $0 +is set from argument zero when the shell +is invoked. +.TP +\f3${\fP\f2parameter\^\fP\f3:\-\fP\f2word\^\fP\f3}\fP +If +.I parameter\^ +is set and is non-null then substitute its value; +otherwise substitute +.IR word . +.TP +\f3${\fP\f2parameter\^\fP\f3:=\fP\f2word\^\fP\f3}\fP +If +.I parameter\^ +is not set or is null +then set it to +.IR word ; +the value of the parameter is then substituted. +Positional parameters may not be assigned to +in this way. +.TP +\f3${\fP\f2parameter\^\fP\f3:?\fP\f2word\^\fP\f3}\fP +If +.I parameter\^ +is set and is non-null then substitute its value; +otherwise, print +.I word\^ +and exit from the shell. +If +.I word\^ +is omitted, then the message +``parameter null or not set'' +is printed. +.TP +\f3${\fP\f2parameter\^\fP\f3:+\fP\f2word\^\fP\f3}\fP +If +.I parameter\^ +is set and is non-null then substitute +.IR word ; +otherwise substitute nothing. +.PD +.PP +In the above, +.I word\^ +is not evaluated unless it is +to be used as the substituted string, +so that, in the following example, +.B pwd +is executed only if +.B d +is not set or is null: +.RS +.PP +echo \|${d:\-\^\*`\^pwd\^\*`\^} +.RE +.PP +If the colon +.RB ( : ) +is omitted from the above expressions, then the +shell only checks whether +.I parameter\^ +is set or not. +.PP +The following +parameters +are automatically set by the shell: +.RS +.PD 0 +.TP +.B # +The number of positional parameters in decimal. +.TP +.B \- +Flags supplied to the shell on invocation or by +the +.B set +command. +.TP +.B ? +The decimal value returned by the last synchronously executed command. +.TP +.B $ +The process number of this shell. +.TP +.B ! +The process number of the last background command invoked. +.PD +.RE +.PP +The following +parameters +are used by the shell: +.RS +.PD 0 +.TP +.B +.SM HOME +The default argument (home directory) for the +.I cd\^ +command. +.TP +.B +.SM PATH +The search path for commands (see +.I Execution\^ +below). +.TP +.B +.SM 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 PS1 +Primary prompt string, by default +.RB `` "$ \|" ''. +.TP +.SM +.B PS2 +Secondary prompt string, by default +.RB `` "> \|" ''. +.TP +.SM +.B IFS +Internal field separators, +normally +.BR space , +.BR tab , +and +.BR new-line . +.PD +.RE +.PP +The shell gives default values to +\f3\s-1PATH\s+1\fP, \f3\s-1PS1\s+1\fP, \f3\s-1PS2\s+1\fP, and \f3\s-1IFS\s+1\fP, +while +.SM +.B HOME +and +.SM +.B MAIL +are +not set at all by the shell (although +.SM +.B HOME +.I is\^ +set by +.IR login (1)). +.SS Blank Interpretation. +After parameter and command substitution, +the results of substitution are scanned for internal field separator +characters (those found in +.BR \s-1IFS\s+1 ) +and split into distinct arguments where such characters are found. +Explicit null arguments (\^\f3"\^"\fP or \f3\*'\^\*'\fP\^) are retained. +Implicit null arguments +(those resulting from +.I parameters\^ +that have no values) are removed. +.SS File Name Generation. +Following substitution, each command +.I word\^ +is scanned for +the characters +.BR \(** , +.BR ? , +and +.BR \*(OK . +If one of these characters appears +then the word is regarded as a +.IR 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 / , +as well as the character +.B / +itself, +must be matched explicitly. +.PP +.PD 0 +.RS +.TP +.B \(** +Matches any string, including the null string. +.TP +.B ? +Matches any single character. +.TP +.BR \*(OK .\|.\|.\^ \*(CK +Matches any one of the enclosed characters. +A pair of characters separated by +.B \- +matches any +character lexically between the pair, inclusive. +If the first character following the opening +\`\`\*(OK\'\' +is a +.B "``!''" +then any character not enclosed is matched. +.PD +.RE +.SS Quoting. +The following characters have a special meaning to the shell +and cause termination of a word unless quoted: +.RS +.PP +\f3; & ( ) \(bv < > new-line space tab\fP +.RE +.PP +A character may be +.I quoted\^ +(i.e., made to stand for itself) +by preceding +it with a +.BR \e . +The pair +.B \enew-line +is ignored. +All characters enclosed between a pair of single quote marks (\^\f3\*'\^\*'\fP\^), +except a single quote, +are quoted. +Inside double quote marks +(\f3"\^"\fP), +parameter and command substitution occurs and +.B \e +quotes the characters +.BR \e , +.BR \*` , +\f3"\fP, +and +.BR $ . +.B +"$\(**" +is equivalent to +\f3"$1 \|$2\fP \|.\|.\|.\f3"\fP, +whereas +.B +"$@" +is equivalent to +.B +"$1"\| +.B +"$2"\| +\&.\|.\|.\|. +.SS Prompting. +When used interactively, +the shell prompts with the value of +.SM +.B PS1 +before reading a command. +If at any time a new-line is typed and further input is needed +to complete a command, then the secondary prompt +(i.e., the value of +.BR \s-1PS2\s+1 ) +is issued. +.SS Input/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 +.I not\^ +passed on to the invoked command; +substitution occurs before +.I word\^ +or +.I digit\^ +is used: +.PP +.PD 0 +.TP 14 +.B <word +Use file +.I word\^ +as standard input (file descriptor 0). +.TP +.B >word +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 +.B >\h@-.3m@>word +Use file +.I 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. +.TP +\f3<\h@-.3m@<\fP\*(OK\f3\-\fP\*(CK\f3word\fP +The shell input is read up to a line that is the same as +.IR word , +or to an 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, +(unescaped) +.B \enew-line +is ignored, +and +.B \e +must be used to quote the characters +.BR \e , +.BR $ , +.BR \*` , +and the first character of +.IR word . +If +.B \- +is appended to +.BR <\h@-.3m@< , +then all leading tabs are stripped from +.I word\^ +and from the document. +.TP +.B <&digit +The standard input is duplicated from file descriptor +.I digit\^ +(see +.IR dup (2)). +Similarly for the standard output using +.BR > . +.TP +.B <&\- +The standard input is closed. +Similarly for the standard output using +.BR > . +.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: +.RS +.PP +\&.\|.\|. \|2>&1 +.RE +.PP +creates file descriptor 2 that is 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 +.BR /dev/null . +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 +.I environment\^ +(see +.IR environ (7)) +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 values of these +parameters +or creates new ones, +none of these affects the environment +unless the +.B export +command is used to bind the shell's +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 +.B export +commands. +.PP +The environment for any +.I simple-command\^ +may be augmented by prefixing it with one or more assignments to +parameters. +Thus: +.RS +.PP +\s-1TERM\s+1=450 \|cmd \|args and +.br +(export \|\s-1TERM\s+1; \|\s-1TERM\s+1=450; \|cmd \|args) +.RE +.PP +are equivalent (as far as the above execution of +.I cmd\^ +is concerned). +.PP +If the +.B \-k +flag is set, +.I all\^ +keyword arguments are placed in the environment, +even if they occur after the command name. +The following +first prints +.B "a=b c" +and then +.BR c: +.PP +.RS +.nf +echo \|a=b \|c +set \|\-k +echo \|a=b \|c +.fi +.RE +.SS Signals. +The \s-1INTERRUPT\s+1 and \s-1QUIT\s+1 signals for an invoked +command are ignored if the command is followed by +.BR & ; +otherwise signals have the values +inherited by the shell from its parent, +with the exception of signal 11 +(but see also +the +.B trap +command below). +.SS Execution. +Each time a command is executed, the above substitutions +are carried out. +Except for the +.I "Special Commands\^" +listed below, a new +process is created and +an attempt is made to execute the command via +.IR exec (2). +.PP +The shell parameter +.B +.SM PATH +defines the search path for +the directory containing the command. +Alternative directory names are separated by +a colon +.RB ( : ). +The default path is +.B :/bin:/usr/bin +(specifying the current directory, +.BR /bin , +and +.BR /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 \f3/\fP 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 +.B a.out +file, +it is assumed to be a file containing shell commands. +A sub-shell (i.e., a separate process) is spawned to read it. +A parenthesized command is also executed in +a sub-shell. +.SS Special Commands. +The following commands are executed in the shell process +and, except as specified, +no input/output redirection is permitted for such commands: +.PP +.PD 0 +.TP +.B : +No effect; the command does nothing. +A zero exit code is returned. +.br +.TP +.BI ".\| " file\^ +Read and execute commands from +.I file\^ +and return. +The search path +specified by +.B +.SM PATH +is used to find the directory containing +.IR file . +.TP +\f3break\fP \*(OK \f2n\^\fP \*(CK +Exit from the enclosing \f3for\fP or +.B while +loop, if any. +If +.I n\^ +is specified then break +.I n\^ +levels. +.TP +\f3continue\fP \*(OK \f2n\^\fP \*(CK +Resume the next iteration of the enclosing +\f3for\fP or +.B while +loop. +If +.I n\^ +is specified then resume at the +.IR n -th +enclosing loop. +.TP +\f3cd\fP \*(OK \f2arg\^\fP \*(CK +Change the current directory to +.IR arg . +The shell +parameter +.B +.SM HOME +is the default +.IR arg . +.br +.ne 2.1v +.TP +\f3eval\fP \*(OK \f2arg\^\fP .\|.\|. \*(CK +The arguments are read as input +to the shell +and the resulting command(s) executed. +.TP +\f3exec\fP \*(OK \f2arg\^\fP .\|.\|. \*(CK +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 +\f3exit\fP \*(OK \f2n\^\fP \*(CK +Causes a shell to exit +with the exit status specified by +.IR n . +If +.I n\^ +is omitted then the exit status is that of the last command executed +(an end-of-file will also cause the shell to exit.) +.TP +\f3export\fP \*(OK \f2name\^\fP .\|.\|. \*(CK +The given +.IR name s +are marked +for automatic export to the +.I environment\^ +of subsequently-executed commands. +If no arguments are given, then a list of all +names that are exported in this shell is printed. +.TP +\f3newgrp\fP \*(OK \f2arg\^\fP .\|.\|. \*(CK +Equivalent to +.BI "exec newgrp" " arg\^" +\&.\|.\|.\|. +.TP +\f3read\fP \*(OK \f2name\^\fP .\|.\|. \*(CK +One line is read from the standard input and +the first +word is assigned to the first +.IR name , +the second word +to the second +.IR name , +etc., with leftover words assigned to the last +.IR name . +The return code is 0 unless an end-of-file is encountered. +.TP +\f3readonly\fP \*(OK \f2name\^\fP .\|.\|. \*(CK +The given +.IR name s +are marked +.I readonly\^ +and +the values of the these +.IR name s +may not be changed +by subsequent assignment. +If no arguments are given, then a list +of all +.I readonly\^ +names is printed. +.TP +\f3set\fP \*(OK \f3\-ekntuvx\fP \*(OK \f2arg\^\fP .\|.\|. \*(CK \*(CK +.RS +.TP +.B \-e +If the shell is non-interactive then exit immediately if a command +exits with a non-zero exit status. +.TP +.B \-k +All keyword arguments are placed in the environment for a command, +not just those that precede the command name. +.TP +.B \-n +Read commands but do not execute them. +.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 \-\- +Do not change any of the flags; useful in setting $1 to -. +.PP +Using +.B \+ +rather than +.B \- +causes these flags to be turned off. +These flags can also be used upon invocation of the shell. +The current set of flags may be found in +.BR $\- . +The remaining arguments are positional +parameters and are assigned, in order, to +.BR $1 , +.BR $2 , +\&.\|.\|.\|. +If no arguments are given then the values +of all names are printed. +.RE +.TP +\f3shift\fP +.br +The positional parameters from +.B $2 +\&.\|.\|. +are renamed +.B $1 +\&.\|.\|.\|. +.TP +\f3test\fP +.br +Evaluate conditional expressions. See +.IR test (1) +for usage and description. +.TP +\f3times\fP +.br +Print the accumulated user and system times for processes +run from the shell. +.TP +\f3trap\fP \*(OK \f2arg\^\fP \*(CK \*(OK \f2n\^\fP \*(CK .\|.\|. +.I arg\^ +is a command to be read and executed when the shell +receives signal(s) +.IR n . +(Note that +.I arg\^ +is scanned once when +the trap is set and once when the trap +is taken.) +Trap commands are executed in order of signal number. +Any attempt to set a trap on a signal that +was ignored on entry to the current shell +is ineffective. +An attempt to trap on signal 11 (memory fault) produces an error. +If +.I arg\^ +is absent then all trap(s) +.I n\^ +are reset +to their original values. +If +.I arg\^ +is the null +string then this signal is ignored by the shell and by the commands +it invokes. +If +.I n\^ +is 0 then the command +.I arg\^ +is executed +on exit from the shell. +The +.B trap +command +with no arguments prints a list +of commands associated with each signal number. +.TP +\f3umask\fP \*(OK \f2nnn\^\fP \*(CK +The user file-creation mask is set to +.I nnn\^ +(see +.IR umask (2)). +If +.I nnn\^ +is omitted, the current value of the mask is printed. +.TP +\f3wait\fP +Wait for all child processes to terminate +report the termination status. +If +.I n\^ +is not given then all currently active child processes are waited for. +The return code from this command is always zero. +.PD +.PP +.SS Invocation. +If the shell is invoked through +.IR exec (2) +and the first character of argument zero +is +.BR \- , +commands are initially read from +.B /etc/profile +and then from +.BR \s-1$HOME\s+1/.profile , +if such files exist. +Thereafter, commands are read as described below, which +is also the case when the shell is invoked as +.BR /bin/sh . +The flags below are interpreted by the shell on invocation only; Note +that unless the +.B \-c +or +.B \-s +flag is specified, the first 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: +.PP +.PD 0 +.TP 10 +.BI \-c "\| string\^" +If the +.B \-c +flag is present then +commands are read from +.IR string . +.TP +.B \-s +If the +.B \-s +flag is present or if no +arguments remain +then commands are read from the standard input. +Any remaining arguments specify the positional parameters. +Shell output is written to +file descriptor 2. +.TP +.B \-i +If the +.B \-i +flag is present or +if the shell input and output are attached to a terminal, +then this shell is +.IR interactive . +In this case \s-1TERMINATE\s+1 is ignored (so that \f3kill 0\fP +does not kill an interactive shell) and \s-1INTERRUPT\s+1 is caught and ignored +(so that +.B wait +is interruptible). +In all cases, \s-1QUIT\s+1 is ignored by the shell. +.PD +.PP +The remaining flags and arguments are described under the +.B set +command above. +.PP +.SH EXIT STATUS +Errors detected by the shell, such as syntax errors, +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 the +.B exit +command above). +.SH FILES +/etc/profile +.br +\s-1$HOME\s+1/\f3.\fPprofile +.br +/tmp/sh\(** +.br +/dev/null +.SH SEE ALSO +cd(1), +env(1), +login(1), +newgrp(1), +rsh(1), +test(1), +umask(1), +dup(2), +exec(2), +fork(2), +pipe(2), +signal(2), +ulimit(2), +umask(2), +wait(2), +a.out(5), +profile(5), +environ(7). +.SH BUGS +The command +.B readonly +(without arguments) produces the same output as the command +.BR export . +.br +If +.B <\h@-.3m@< +is used to provide standard input to an +asynchronous process invoked by +.BR & , +the shell gets mixed up about naming +the input document; +a garbage file +.B /tmp/sh\(** +is created and the shell complains about not being able +to find that file by another name. |