readline.0

在非GUI环境下

READLINE(3)                                                        READLINE(3)



NNAAMMEE
       readline - get a line from a user with editing

SSYYNNOOPPSSIISS
       ##iinncclluuddee <<ssttddiioo..hh>>
       ##iinncclluuddee <<rreeaaddlliinnee//rreeaaddlliinnee..hh>>
       ##iinncclluuddee <<rreeaaddlliinnee//hhiissttoorryy..hh>>

       _c_h_a_r _*
       rreeaaddlliinnee (_c_o_n_s_t _c_h_a_r _*_p_r_o_m_p_t);

CCOOPPYYRRIIGGHHTT
       Readline  is  Copyright  (C) 1989-2004 by the Free Software Foundation,
       Inc.

DDEESSCCRRIIPPTTIIOONN
       rreeaaddlliinnee will read a line from the terminal and return it, using pprroommpptt
       as  a  prompt.   If  pprroommpptt  is  NNUULLLL or the empty string, no prompt is
       issued.  The line returned is allocated with _m_a_l_l_o_c(3); the caller must
       free  it  when  finished.   The  line  returned  has  the final newline
       removed, so only the text of the line remains.

       rreeaaddlliinnee offers editing capabilities while the  user  is  entering  the
       line.   By  default,  the line editing commands are similar to those of
       emacs.  A vi-style line editing interface is also available.

       This manual page describes only the most basic use of  rreeaaddlliinnee.   Much
       more  functionality  is available; see _T_h_e _G_N_U _R_e_a_d_l_i_n_e _L_i_b_r_a_r_y and _T_h_e
       _G_N_U _H_i_s_t_o_r_y _L_i_b_r_a_r_y for additional information.

RREETTUURRNN VVAALLUUEE
       rreeaaddlliinnee returns the text of the line read.  A blank line  returns  the
       empty string.  If EEOOFF is encountered while reading a line, and the line
       is empty, NNUULLLL is returned.  If an EEOOFF is read with a  non-empty  line,
       it is treated as a newline.

NNOOTTAATTIIOONN
       An emacs-style notation is used to denote keystrokes.  Control keys are
       denoted by C-_k_e_y, e.g., C-n means Control-N.  Similarly, _m_e_t_a keys  are
       denoted  by  M-_k_e_y,  so M-x means Meta-X.  (On keyboards without a _m_e_t_a
       key, M-_x means ESC _x, i.e., press the Escape key then the _x key.   This
       makes  ESC the _m_e_t_a _p_r_e_f_i_x.  The combination M-C-_x means ESC-Control-_x,
       or press the Escape key then hold the Control key while pressing the  _x
       key.)

       Readline commands may be given numeric _a_r_g_u_m_e_n_t_s, which normally act as
       a repeat count.  Sometimes, however, it is the  sign  of  the  argument
       that  is  significant.   Passing  a negative argument to a command that
       acts in the forward direction (e.g., kkiillll--lliinnee) causes that command  to
       act  in  a  backward direction.  Commands whose behavior with arguments
       deviates from this are noted.

       When a command is described as _k_i_l_l_i_n_g text, the text deleted is  saved
       for possible future retrieval (_y_a_n_k_i_n_g).  The killed text is saved in a
       _k_i_l_l _r_i_n_g.  Consecutive kills cause the text to be accumulated into one
       unit, which can be yanked all at once.  Commands which do not kill text
       separate the chunks of text on the kill ring.

IINNIITTIIAALLIIZZAATTIIOONN FFIILLEE
       Readline is customized by putting commands in  an  initialization  file
       (the  _i_n_p_u_t_r_c  file).  The name of this file is taken from the value of
       the IINNPPUUTTRRCC environment variable.   If  that  variable  is  unset,  the
       default  is _~_/_._i_n_p_u_t_r_c.  When a program which uses the readline library
       starts up, the init file is read, and the key  bindings  and  variables
       are set.  There are only a few basic constructs allowed in the readline
       init file.  Blank lines are ignored.  Lines beginning with a ## are com-
       ments.   Lines  beginning  with  a  $$  indicate conditional constructs.
       Other lines denote key bindings and variable  settings.   Each  program
       using this library may add its own commands and bindings.

       For example, placing

              M-Control-u: universal-argument
       or
              C-Meta-u: universal-argument

       into  the _i_n_p_u_t_r_c would make M-C-u execute the readline command _u_n_i_v_e_r_-
       _s_a_l_-_a_r_g_u_m_e_n_t.

       The following symbolic character names are recognized while  processing
       key  bindings:  _D_E_L,  _E_S_C,  _E_S_C_A_P_E,  _L_F_D, _N_E_W_L_I_N_E, _R_E_T, _R_E_T_U_R_N, _R_U_B_O_U_T,
       _S_P_A_C_E, _S_P_C, and _T_A_B.

       In addition to command names, readline allows keys to  be  bound  to  a
       string that is inserted when the key is pressed (a _m_a_c_r_o).


   KKeeyy BBiinnddiinnggss
       The  syntax for controlling key bindings in the _i_n_p_u_t_r_c file is simple.
       All that is required is the name of the command or the text of a  macro
       and  a key sequence to which it should be bound. The name may be speci-
       fied in one of two ways: as a symbolic key name, possibly with _M_e_t_a_- or
       _C_o_n_t_r_o_l_- prefixes, or as a key sequence.

       When using the form kkeeyynnaammee:_f_u_n_c_t_i_o_n_-_n_a_m_e or _m_a_c_r_o, _k_e_y_n_a_m_e is the name
       of a key spelled out in English.  For example:

              Control-u: universal-argument
              Meta-Rubout: backward-kill-word
              Control-o: "> output"

       In the above example, _C_-_u is bound to the function  uunniivveerrssaall--aarrgguummeenntt,
       _M_-_D_E_L  is bound to the function bbaacckkwwaarrdd--kkiillll--wwoorrdd, and _C_-_o is bound to
       run the macro expressed on the right hand side (that is, to insert  the
       text ``> output'' into the line).

       In  the  second  form,  ""kkeeyysseeqq"":_f_u_n_c_t_i_o_n_-_n_a_m_e or _m_a_c_r_o, kkeeyysseeqq differs
       from kkeeyynnaammee above in that strings denoting an entire key sequence  may
       be  specified  by  placing the sequence within double quotes.  Some GNU
       Emacs style key escapes can be used, as in the following  example,  but
       the symbolic character names are not recognized.

              "\C-u": universal-argument
              "\C-x\C-r": re-read-init-file
              "\e[11~": "Function Key 1"

       In this example, _C_-_u is again bound to the function uunniivveerrssaall--aarrgguummeenntt.
       _C_-_x _C_-_r is bound to the function rree--rreeaadd--iinniitt--ffiillee, and _E_S_C _[ _1 _1 _~  is
       bound to insert the text ``Function Key 1''.

       The  full set of GNU Emacs style escape sequences available when speci-
       fying key sequences is
              \\CC--    control prefix
              \\MM--    meta prefix
              \\ee     an escape character
              \\\\     backslash
              \\""     literal ", a double quote
              \\''     literal ', a single quote

       In addition to the GNU Emacs style escape sequences, a  second  set  of
       backslash escapes is available:
              \\aa     alert (bell)
              \\bb     backspace
              \\dd     delete
              \\ff     form feed
              \\nn     newline
              \\rr     carriage return
              \\tt     horizontal tab
              \\vv     vertical tab
              \\_n_n_n   the  eight-bit  character  whose value is the octal value
                     _n_n_n (one to three digits)
              \\xx_H_H   the eight-bit character whose value  is  the  hexadecimal
                     value _H_H (one or two hex digits)

       When  entering  the  text of a macro, single or double quotes should be
       used to indicate a macro definition.  Unquoted text is assumed to be  a
       function  name.   In  the  macro  body, the backslash escapes described
       above are expanded.  Backslash will quote any other  character  in  the
       macro text, including " and '.

       BBaasshh  allows the current readline key bindings to be displayed or modi-
       fied with the bbiinndd builtin command.  The editing mode may  be  switched
       during  interactive  use by using the --oo option to the sseett builtin com-
       mand.  Other programs using this library  provide  similar  mechanisms.
       The  _i_n_p_u_t_r_c  file may be edited and re-read if a program does not pro-
       vide any other means to incorporate new bindings.

   VVaarriiaabblleess
       Readline has variables that can be used to further customize its behav-
       ior.  A variable may be set in the _i_n_p_u_t_r_c file with a statement of the
       form

              sseett _v_a_r_i_a_b_l_e_-_n_a_m_e _v_a_l_u_e

       Except where noted, readline variables can take the values  OOnn  or  OOffff
       (without regard to case).  The variables and their default values are:

       bbeellll--ssttyyllee ((aauuddiibbllee))
              Controls  what  happens when readline wants to ring the terminal
              bell.  If set to nnoonnee, readline never rings the bell.  If set to
              vviissiibbllee,  readline  uses a visible bell if one is available.  If
              set to aauuddiibbllee, readline attempts to ring the terminal's bell.
       ccoommmmeenntt--bbeeggiinn ((````##''''))
              The string that is inserted in vvii mode when  the  iinnsseerrtt--ccoommmmeenntt
              command is executed.  This command is bound to MM--## in emacs mode
              and to ## in vi command mode.
       ccoommpplleettiioonn--iiggnnoorree--ccaassee ((OOffff))
              If set to OOnn, readline performs filename matching and completion
              in a case-insensitive fashion.
       ccoommpplleettiioonn--qquueerryy--iitteemmss ((110000))
              This  determines when the user is queried about viewing the num-
              ber of possible completions generated  by  the  ppoossssiibbllee--ccoommppllee--
              ttiioonnss  command.  It may be set to any integer value greater than
              or equal to zero.  If the  number  of  possible  completions  is
              greater than or equal to the value of this variable, the user is
              asked whether or not he wishes to view them; otherwise they  are
              simply listed on the terminal.
       ccoonnvveerrtt--mmeettaa ((OOnn))
              If  set  to OOnn, readline will convert characters with the eighth
              bit set to an ASCII key sequence by stripping the eighth bit and
              prefixing  it  with an escape character (in effect, using escape
              as the _m_e_t_a _p_r_e_f_i_x).
       ddiissaabbllee--ccoommpplleettiioonn ((OOffff))
              If set to OOnn, readline will inhibit word completion.  Completion
              characters  will  be  inserted into the line as if they had been
              mapped to sseellff--iinnsseerrtt.
       eeddiittiinngg--mmooddee ((eemmaaccss))
              Controls whether readline begins with a set of key bindings sim-
              ilar to emacs or vi.  eeddiittiinngg--mmooddee can be set to either eemmaaccss or
              vvii.
       eennaabbllee--kkeeyyppaadd ((OOffff))
              When set to OOnn, readline will try to enable the application key-
              pad  when  it  is  called.  Some systems need this to enable the
              arrow keys.
       eexxppaanndd--ttiillddee ((OOffff))
              If set  to  oonn,  tilde  expansion  is  performed  when  readline
              attempts word completion.
       hhiissttoorryy--pprreesseerrvvee--ppooiinntt
              If  set  to  oonn, the history code attempts to place point at the
              same location on each history line retrived  with  pprreevviioouuss--hhiiss--
              ttoorryy or nneexxtt--hhiissttoorryy.
       hhoorriizzoonnttaall--ssccrroollll--mmooddee ((OOffff))
              When  set  to  OOnn, makes readline use a single line for display,
              scrolling the input horizontally on a single screen line when it
              becomes  longer  than the screen width rather than wrapping to a
              new line.
       iinnppuutt--mmeettaa ((OOffff))
              If set to OOnn, readline will enable eight-bit input (that is,  it
              will  not  clear  the  eighth  bit  in the characters it reads),
              regardless of what the terminal claims it can support.  The name
              mmeettaa--ffllaagg is a synonym for this variable.
       iisseeaarrcchh--tteerrmmiinnaattoorrss ((````CC--[[ CC--JJ''''))
              The  string  of  characters that should terminate an incremental
              search without subsequently executing the character  as  a  com-
              mand.   If this variable has not been given a value, the charac-