/usr/bin/bash: Difference between revisions

:Display current readline key and function bindings, bind a  key  sequence  to  a  readline function  or  macro, or set a readline variable. Each non-option argument is a command as it would appear in .inputrc, but each binding or command must be passed as a separate  argument;  e.g.,  '"\C-x\C-r": re-read-init-file'.  Options, if supplied, have the following meanings:

:::Use keymap as the keymap to be affected by the  subsequent  bindings.  Acceptable keymap  names  are  emacs,  emacs-standard,  emacs-meta,  emacs-ctlx,  vi, vi-move, vi-command, and vi-insert.  vi is equivalent to vi-command (vi-move is also a  synonym); emacs is equivalent to emacs-standard.

:::List the names of all readline functions.

:::Display  readline  function  names  and bindings in such a way that they can be re-read.

:::List current readline function names and bindings.

:::Display readline key sequences bound to macros and the strings they output in  such a way that they can be re-read.

:::Display readline key sequences bound to macros and the strings they output.

:::Display readline variable names and values in such a way that they can be re-read.

:::List current readline variable names and values.

:::Read key bindings from filename.

:::Query about which keys invoke the named function.

:::Unbind all keys bound to the named function.

:::Remove any current binding for keyseq.

:::Cause  shell-command to be executed whenever keyseq is entered.  When shell-command is executed, the shell sets the READLINE_LINE variable to the contents of the read‐line  line buffer and the READLINE_POINT and READLINE_MARK variables to the current location of the insertion point and the saved insertion point (the mark),  respectively.  If  the executed command changes the value of any of READLINE_LINE, READLINE_POINT, or READLINE_MARK, those new values will be reflected  in  the  editing state.

:::List  all  key  sequences  bound to shell commands and the associated commands in a format that can be reused as input.

:Exit from within a for, while, until, or select loop.  If n is specified, break n  levels. n  must  be  ≥ 1.  If n is greater than the number of enclosing loops, all enclosing loops are exited.  The return value is 0 unless n is not greater than or equal to 1.

:Execute the specified shell builtin, passing it arguments, and  return  its  exit  status. This is useful when defining a function whose name is the same as a shell builtin, retaining the functionality of the builtin within the function.  The cd builtin is commonly  redefined this way.  The return status is false if shell-builtin is not a shell builtin command.

:Returns the context of any active subroutine call (a shell function or a  script  executed with  the . or source builtins).  Without expr, caller displays the line number and source filename of the current subroutine call.  If a non-negative integer is supplied  as  expr, caller  displays  the  line number, subroutine name, and source file corresponding to that position in the current execution call stack.  This extra information may be used, for example,  to  print a stack trace.  The current frame is frame 0.  The return value is 0 unless the shell is not executing a subroutine call or expr does not correspond to  a  valid position in the call stack.

:Change  the current directory to dir.  if dir is not supplied, the value of the HOME shell variable is the default.  Any additional arguments following dir are ignored.  The  variable CDPATH defines the search path for the directory containing dir: each directory name in CDPATH is searched for dir.  Alternative directory names in CDPATH are separated  by  a colon  (:).  A null directory name in CDPATH is the same as the current directory, i.e., ``.''.  If dir begins with a slash (/), then CDPATH is not used. The -P option causes  cd to  use  the physical directory structure by resolving symbolic links while traversing dir and before processing instances of .. in dir (see also the -P option to  the  set  builtin command);  the  -L option forces symbolic links to be followed by resolving the link after processing instances of .. in dir.  If .. appears in dir, it is processed by removing  the immediately previous pathname component from dir, back to a slash or the beginning of dir. If the -e option is supplied with -P, and the current working directory cannot be successfully  determined after a successful directory change, cd will return an unsuccessful status.  On systems that support it, the -@ option presents the extended  attributes  associated  with a file as a directory.  An argument of - is converted to $OLDPWD before the directory change is attempted.  If a non-empty directory name from CDPATH is used, or  if  - is  the  first  argument, and the directory change is successful, the absolute pathname of the new working directory is written to the standard output.  The return value is true  if the directory was successfully changed; false otherwise.

:Run command with args suppressing the normal shell function lookup.  Only builtin commands or commands found in the PATH are executed.  If the -p option is  given,  the  search  for command  is performed using a default value for PATH that is guaranteed to find all of the standard utilities.  If either the -V or -v option is supplied, a description  of  command is printed.  The -v option causes a single word indicating the command or filename used to invoke command to be displayed; the -V option produces a more verbose description.  If the -V  or -v option is supplied, the exit status is 0 if command was found, and 1 if not.  If neither option is supplied and an error occurred or command cannot be found, the exit status  is 127.  Otherwise, the exit status of the command builtin is the exit status of command.