Translations by Jen Ockwell

syntax error: invalid arithmetic operator

forked pid %d appears in running job %d

Copyright (C) 2006 Free Software Foundation, Inc.

`alias' with no arguments or with the -p option prints the list of aliases in the form alias NAME=VALUE on standard output. Otherwise, an alias is defined for each NAME whose VALUE is given. A trailing space in VALUE causes the next word to be checked for alias substitution when the alias is expanded. Alias returns true unless a NAME is given for which no alias has been defined.

Remove NAMEs from the list of defined aliases. If the -a option is given, then remove all alias definitions.

Bind a key sequence to a Readline function or a macro, or set a Readline variable. The non-option argument syntax is equivalent to that found in ~/.inputrc, but must be passed as a single argument: bind '"\C-x\C-r": re-read-init-file'. bind accepts the following options: -m keymap Use `keymap' as the keymap for the duration of this command. Acceptable keymap names are emacs, emacs-standard, emacs-meta, emacs-ctlx, vi, vi-move, vi-command, and vi-insert. -l List names of functions. -P List function names and bindings. -p List functions and bindings in a form that can be reused as input. -r keyseq Remove the binding for KEYSEQ. -x keyseq:shell-command Cause SHELL-COMMAND to be executed when KEYSEQ is entered. -f filename Read key bindings from FILENAME. -q function-name Query about which keys invoke the named function. -u function-name Unbind all keys which are bound to the named function. -V List variable names and values -v List variable names and values in a form that can be reused as input. -S List key sequences that invoke macros and their values -s List key sequences that invoke macros and their values in a form that can be reused as input.

Exit from within a FOR, WHILE or UNTIL loop. If N is specified, break N levels.

Resume the next iteration of the enclosing FOR, WHILE or UNTIL loop. If N is specified, resume at the N-th enclosing loop.

Run a shell builtin. This is useful when you wish to rename a shell builtin to be a function, but need the functionality of the builtin within the function itself.

Returns the context of the current subroutine call. Without EXPR, returns "$line $filename". With EXPR, returns "$line $subroutine $filename"; this extra information can be used to provide a stack trace. The value of EXPR indicates how many call frames to go back before the current one; the top frame is frame 0.

Change the current directory to DIR. The variable $HOME is the default DIR. The variable CDPATH defines the search path for the directory containing DIR. Alternative directory names in CDPATH are separated by a colon (:). A null directory name is the same as the current directory, i.e. `.'. If DIR begins with a slash (/), then CDPATH is not used. If the directory is not found, and the shell option `cdable_vars' is set, then try the word as a variable name. If that variable has a value, then cd to the value of that variable. The -P option says to use the physical directory structure instead of following symbolic links; the -L option forces symbolic links to be followed.

Print the current working directory. With the -P option, pwd prints the physical directory, without any symbolic links; the -L option makes pwd follow symbolic links.

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

Return a successful result.

Return an unsuccessful result.

Runs COMMAND with ARGS ignoring shell functions. If you have a shell function called `ls', and you wish to call the command `ls', you can say "command ls". If the -p option is given, a default value is used for PATH that is guaranteed to find all of the standard utilities. If the -V or -v option is given, a string is printed describing COMMAND. The -V option produces a more verbose description.

Declare variables and/or give them attributes. If no NAMEs are given, then display the values of variables instead. The -p option will display the attributes and values of each NAME. The flags are: -a to make NAMEs arrays (if supported) -f to select from among function names only -F to display function names (and line number and source file name if debugging) without definitions -i to make NAMEs have the `integer' attribute -r to make NAMEs readonly -t to make NAMEs have the `trace' attribute -x to make NAMEs export Variables with the integer attribute have arithmetic evaluation (see `let') done when the variable is assigned to. When displaying values of variables, -f displays a function's name and definition. The -F option restricts the display to function name only. Using `+' instead of `-' turns off the given attribute instead. When used in a function, makes NAMEs local, as with the `local' command.

Obsolete. See `declare'.

Create a local variable called NAME, and give it VALUE. LOCAL can only be used within a function; it makes the variable NAME have a visible scope restricted to that function and its children.

Output the ARGs. If -n is specified, the trailing newline is suppressed. If the -e option is given, interpretation of the following backslash-escaped characters is turned on: \a alert (bell) \b backspace \c suppress trailing newline \E escape character \f form feed \n new line \r carriage return \t horizontal tab \v vertical tab \\ backslash \0nnn the character whose ASCII code is NNN (octal). NNN can be 0 to 3 octal digits You can explicitly turn off the interpretation of the above characters with the -E option.

Output the ARGs. If -n is specified, the trailing newline is suppressed.

Enable and disable builtin shell commands. This allows you to use a disk command which has the same name as a shell builtin without specifying a full pathname. If -n is used, the NAMEs become disabled; otherwise NAMEs are enabled. For example, to use the `test' found in $PATH instead of the shell builtin version, type `enable -n test'. On systems supporting dynamic loading, the -f option may be used to load new builtins from the shared object FILENAME. The -d option will delete a builtin previously loaded with -f. If no non-option names are given, or the -p option is supplied, a list of builtins is printed. The -a option means to print every builtin with an indication of whether or not it is enabled. The -s option restricts the output to the POSIX.2 `special' builtins. The -n option displays a list of all disabled builtins.

Read ARGs as input to the shell and execute the resulting command(s).

Getopts is used by shell procedures to parse positional parameters. OPTSTRING contains the option letters to be recognized; if a letter is followed by a colon, the option is expected to have an argument, which should be separated from it by white space. Each time it is invoked, getopts will place the next option in the shell variable $name, initializing name if it does not exist, and the index of the next argument to be processed into the shell variable OPTIND. OPTIND is initialized to 1 each time the shell or a shell script is invoked. When an option requires an argument, getopts places that argument into the shell variable OPTARG. getopts reports errors in one of two ways. If the first character of OPTSTRING is a colon, getopts uses silent error reporting. In this mode, no error messages are printed. If an invalid option is seen, getopts places the option character found into OPTARG. If a required argument is not found, getopts places a ':' into NAME and sets OPTARG to the option character found. If getopts is not in silent mode, and an invalid option is seen, getopts places '?' into NAME and unsets OPTARG. If a required argument is not found, a '?' is placed in NAME, OPTARG is unset, and a diagnostic message is printed. If the shell variable OPTERR has the value 0, getopts disables the printing of error messages, even if the first character of OPTSTRING is not a colon. OPTERR has the value 1 by default. Getopts normally parses the positional parameters ($0 - $9), but if more arguments are given, they are parsed instead.

Exec FILE, replacing this shell with the specified program. If FILE is not specified, the redirections take effect in this shell. If the first argument is `-l', then place a dash in the zeroth arg passed to FILE, as login does. If the `-c' option is supplied, FILE is executed with a null environment. The `-a' option means to make set argv[0] of the executed process to NAME. If the file cannot be executed and the shell is not interactive, then the shell exits, unless the shell option `execfail' is set.

Exit the shell with a status of N. If N is omitted, the exit status is that of the last command executed.

Logout of a login shell.

fc is used to list or edit and re-execute commands from the history list. FIRST and LAST can be numbers specifying the range, or FIRST can be a string, which means the most recent command beginning with that string. -e ENAME selects which editor to use. Default is FCEDIT, then EDITOR, then vi. -l means list lines instead of editing. -n means no line numbers listed. -r means reverse the order of the lines (making it newest listed first). With the `fc -s [pat=rep ...] [command]' format, the command is re-executed after the substitution OLD=NEW is performed. A useful alias to use with this is r='fc -s', so that typing `r cc' runs the last command beginning with `cc' and typing `r' re-executes the last command.

Place JOB_SPEC in the foreground, and make it the current job. If JOB_SPEC is not present, the shell's notion of the current job is used.

Place each JOB_SPEC in the background, as if it had been started with `&'. If JOB_SPEC is not present, the shell's notion of the current job is used.

For each NAME, the full pathname of the command is determined and remembered. If the -p option is supplied, PATHNAME is used as the full pathname of NAME, and no path search is performed. The -r option causes the shell to forget all remembered locations. The -d option causes the shell to forget the remembered location of each NAME. If the -t option is supplied the full pathname to which each NAME corresponds is printed. If multiple NAME arguments are supplied with -t, the NAME is printed before the hashed full pathname. The -l option causes output to be displayed in a format that may be reused as input. If no arguments are given, information about remembered commands is displayed.

Display helpful information about builtin commands. If PATTERN is specified, gives detailed help on all commands matching PATTERN, otherwise a list of the builtins is printed. The -s option restricts the output for each builtin command matching PATTERN to a short usage synopsis.

Display the history list with line numbers. Lines listed with with a `*' have been modified. Argument of N says to list only the last N lines. The `-c' option causes the history list to be cleared by deleting all of the entries. The `-d' option deletes the history entry at offset OFFSET. The `-w' option writes out the current history to the history file; `-r' means to read the file and append the contents to the history list instead. `-a' means to append history lines from this session to the history file. Argument `-n' means to read all history lines not already read from the history file and append them to the history list. If FILENAME is given, then that is used as the history file else if $HISTFILE has a value, that is used, else ~/.bash_history. If the -s option is supplied, the non-option ARGs are appended to the history list as a single entry. The -p option means to perform history expansion on each ARG and display the result, without storing anything in the history list. If the $HISTTIMEFORMAT variable is set and not null, its value is used as a format string for strftime(3) to print the time stamp associated with each displayed history entry. No time stamps are printed otherwise.

Lists the active jobs. The -l option lists process id's in addition to the normal information; the -p option lists process id's only. If -n is given, only processes that have changed status since the last notification are printed. JOBSPEC restricts output to that job. The -r and -s options restrict output to running and stopped jobs only, respectively. Without options, the status of all active jobs is printed. If -x is given, COMMAND is run after all job specifications that appear in ARGS have been replaced with the process ID of that job's process group leader.

By default, removes each JOBSPEC argument from the table of active jobs. If the -h option is given, the job is not removed from the table, but is marked so that SIGHUP is not sent to the job if the shell receives a SIGHUP. The -a option, when JOBSPEC is not supplied, means to remove all jobs from the job table; the -r option means to remove only running jobs.

Send the processes named by PID (or JOBSPEC) the signal SIGSPEC. If SIGSPEC is not present, then SIGTERM is assumed. An argument of `-l' lists the signal names; if arguments follow `-l' they are assumed to be signal numbers for which names should be listed. Kill is a shell builtin for two reasons: it allows job IDs to be used instead of process IDs, and, if you have reached the limit on processes that you can create, you don't have to start a process to kill another one.

Each ARG is an arithmetic expression to be evaluated. Evaluation is done in fixed-width integers with no check for overflow, though division by 0 is trapped and flagged as an error. The following list of operators is grouped into levels of equal-precedence operators. The levels are listed in order of decreasing precedence. id++, id-- variable post-increment, post-decrement ++id, --id variable pre-increment, pre-decrement -, + unary minus, plus !, ~ logical and bitwise negation ** exponentiation *, /, % multiplication, division, remainder +, - addition, subtraction <<, >> left and right bitwise shifts <=, >=, <, > comparison ==, != equality, inequality & bitwise AND ^ bitwise XOR | bitwise OR && logical AND || logical OR expr ? expr : expr conditional operator =, *=, /=, %=, +=, -=, <<=, >>=, &=, ^=, |= assignment Shell variables are allowed as operands. The name of the variable is replaced by its value (coerced to a fixed-width integer) within an expression. The variable need not have its integer attribute turned on to be used in an expression. Operators are evaluated in order of precedence. Sub-expressions in parentheses are evaluated first and may override the precedence rules above. If the last ARG evaluates to 0, let returns 1; 0 is returned otherwise.

One line is read from the standard input, or from file descriptor FD if the -u option is supplied, and the first word is assigned to the first NAME, the second word to the second NAME, and so on, with leftover words assigned to the last NAME. Only the characters found in $IFS are recognized as word delimiters. If no NAMEs are supplied, the line read is stored in the REPLY variable. If the -r option is given, this signifies `raw' input, and backslash escaping is disabled. The -d option causes read to continue until the first character of DELIM is read, rather than newline. If the -p option is supplied, the string PROMPT is output without a trailing newline before attempting to read. If -a is supplied, the words read are assigned to sequential indices of ARRAY, starting at zero. If -e is supplied and the shell is interactive, readline is used to obtain the line. If -n is supplied with a non-zero NCHARS argument, read returns after NCHARS characters have been read. The -s option causes input coming from a terminal to not be echoed. The -t option causes read to time out and return failure if a complete line of input is not read within TIMEOUT seconds. If the TMOUT variable is set, its value is the default timeout. The return code is zero, unless end-of-file is encountered, read times out, or an invalid file descriptor is supplied as the argument to -u.

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

-a Mark variables which are modified or created for export. -b Notify of job termination immediately. -e Exit immediately if a command exits with a non-zero status. -f Disable file name generation (globbing). -h Remember the location of commands as they are looked up. -k All assignment arguments are placed in the environment for a command, not just those that precede the command name. -m Job control is enabled. -n Read commands but do not execute them. -o option-name Set the variable corresponding to option-name: allexport same as -a braceexpand same as -B emacs use an emacs-style line editing interface errexit same as -e errtrace same as -E functrace same as -T hashall same as -h histexpand same as -H history enable command history ignoreeof the shell will not exit upon reading EOF interactive-comments allow comments to appear in interactive commands keyword same as -k monitor same as -m noclobber same as -C noexec same as -n noglob same as -f nolog currently accepted but ignored notify same as -b nounset same as -u onecmd same as -t physical same as -P pipefail the return value of a pipeline is the status of the last command to exit with a non-zero status, or zero if no command exited with a non-zero status posix change the behavior of bash where the default operation differs from the 1003.2 standard to match the standard privileged same as -p verbose same as -v vi use a vi-style line editing interface xtrace same as -x -p Turned on whenever the real and effective user ids do not match. Disables processing of the $ENV file and importing of shell functions. Turning this option off causes the effective uid and gid to be set to the real uid and gid. -t Exit after reading and executing one command. -u Treat unset variables as an error when substituting. -v Print shell input lines as they are read. -x Print commands and their arguments as they are executed. -B the shell will perform brace expansion -C If set, disallow existing regular files to be overwritten by redirection of output. -E If set, the ERR trap is inherited by shell functions. -H Enable ! style history substitution. This flag is on by default when the shell is interactive. -P If set, do not follow symbolic links when executing commands such as cd which change the current directory. -T If set, the DEBUG trap is inherited by shell functions. - Assign any remaining arguments to the positional parameters. The -x and -v options are turned off. Using + rather than - causes these flags to be turned off. The flags can also be used upon invocation of the shell. The current set of flags may be found in $-. The remaining n ARGs are positional parameters and are assigned, in order, to $1, $2, .. $n. If no ARGs are given, all shell variables are printed.

For each NAME, remove the corresponding variable or function. Given the `-v', unset will only act on variables. Given the `-f' flag, unset will only act on functions. With neither flag, unset first tries to unset a variable, and if that fails, then tries to unset a function. Some variables cannot be unset; also see readonly.

NAMEs are marked for automatic export to the environment of subsequently executed commands. If the -f option is given, the NAMEs refer to functions. If no NAMEs are given, or if `-p' is given, a list of all names that are exported in this shell is printed. An argument of `-n' says to remove the export property from subsequent NAMEs. An argument of `--' disables further option processing.

The given NAMEs are marked readonly and the values of these NAMEs may not be changed by subsequent assignment. If the -f option is given, then functions corresponding to the NAMEs are so marked. If no arguments are given, or if `-p' is given, a list of all readonly names is printed. The `-a' option means to treat each NAME as an array variable. An argument of `--' disables further option processing.

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

Read and execute commands from FILENAME and return. The pathnames in $PATH are used to find the directory containing FILENAME. If any ARGUMENTS are supplied, they become the positional parameters when FILENAME is executed.

Suspend the execution of this shell until it receives a SIGCONT signal. The `-f' if specified says not to complain about this being a login shell if it is; just suspend anyway.

Exits with a status of 0 (true) or 1 (false) depending on the evaluation of EXPR. Expressions may be unary or binary. Unary expressions are often used to examine the status of a file. There are string operators as well, and numeric comparison operators. File operators: -a FILE True if file exists. -b FILE True if file is block special. -c FILE True if file is character special. -d FILE True if file is a directory. -e FILE True if file exists. -f FILE True if file exists and is a regular file. -g FILE True if file is set-group-id. -h FILE True if file is a symbolic link. -L FILE True if file is a symbolic link. -k FILE True if file has its `sticky' bit set. -p FILE True if file is a named pipe. -r FILE True if file is readable by you. -s FILE True if file exists and is not empty. -S FILE True if file is a socket. -t FD True if FD is opened on a terminal. -u FILE True if the file is set-user-id. -w FILE True if the file is writable by you. -x FILE True if the file is executable by you. -O FILE True if the file is effectively owned by you. -G FILE True if the file is effectively owned by your group. -N FILE True if the file has been modified since it was last read. FILE1 -nt FILE2 True if file1 is newer than file2 (according to modification date). FILE1 -ot FILE2 True if file1 is older than file2. FILE1 -ef FILE2 True if file1 is a hard link to file2. String operators: -z STRING True if string is empty. -n STRING STRING True if string is not empty. STRING1 = STRING2 True if the strings are equal. STRING1 != STRING2 True if the strings are not equal. STRING1 < STRING2 True if STRING1 sorts before STRING2 lexicographically. STRING1 > STRING2 True if STRING1 sorts after STRING2 lexicographically. Other operators: -o OPTION True if the shell option OPTION is enabled. ! EXPR True if expr is false. EXPR1 -a EXPR2 True if both expr1 AND expr2 are true. EXPR1 -o EXPR2 True if either expr1 OR expr2 is true. arg1 OP arg2 Arithmetic tests. OP is one of -eq, -ne, -lt, -le, -gt, or -ge. Arithmetic binary operators return true if ARG1 is equal, not-equal, less-than, less-than-or-equal, greater-than, or greater-than-or-equal than ARG2.

This is a synonym for the "test" builtin, but the last argument must be a literal `]', to match the opening `['.

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

The command ARG is to be read and executed when the shell receives signal(s) SIGNAL_SPEC. If ARG is absent (and a single SIGNAL_SPEC is supplied) or `-', each specified signal is reset to its original value. If ARG is the null string each SIGNAL_SPEC is ignored by the shell and by the commands it invokes. If a SIGNAL_SPEC is EXIT (0) the command ARG is executed on exit from the shell. If a SIGNAL_SPEC is DEBUG, ARG is executed after every simple command. If the`-p' option is supplied then the trap commands associated with each SIGNAL_SPEC are displayed. If no arguments are supplied or if only `-p' is given, trap prints the list of commands associated with each signal. Each SIGNAL_SPEC is either a signal name in <signal.h> or a signal number. Signal names are case insensitive and the SIG prefix is optional. `trap -l' prints a list of signal names and their corresponding numbers. Note that a signal can be sent to the shell with "kill -signal $$".