history.0

在非GUI环境下

HISTORY(3)                                                          HISTORY(3)



NNAAMMEE
       history - GNU History Library

CCOOPPYYRRIIGGHHTT
       The GNU History Library is Copyright (C) 1989-2002 by the Free Software
       Foundation, Inc.

DDEESSCCRRIIPPTTIIOONN
       Many programs read input from the user a line at a time.  The GNU  His-
       tory  library is able to keep track of those lines, associate arbitrary
       data with each line, and utilize information  from  previous  lines  in
       composing new ones.


HHIISSTTOORRYY EEXXPPAANNSSIIOONN
       The  history library supports a history expansion feature that is iden-
       tical to the history expansion in bbaasshh..  This  section  describes  what
       syntax features are available.

       History expansions introduce words from the history list into the input
       stream, making it easy to repeat commands, insert the  arguments  to  a
       previous command into the current input line, or fix errors in previous
       commands quickly.

       History expansion is usually performed  immediately  after  a  complete
       line  is read.  It takes place in two parts.  The first is to determine
       which line from the history list to use during substitution.  The  sec-
       ond  is  to select portions of that line for inclusion into the current
       one.  The line selected from the history is the _e_v_e_n_t, and the portions
       of  that  line  that  are  acted upon are _w_o_r_d_s.  Various _m_o_d_i_f_i_e_r_s are
       available to manipulate the selected words.  The line  is  broken  into
       words in the same fashion as bbaasshh does when reading input, so that sev-
       eral words that would otherwise be separated are  considered  one  word
       when  surrounded  by  quotes (see the description of hhiissttoorryy__ttookkeenniizzee(())
       below).  History expansions are introduced by  the  appearance  of  the
       history expansion character, which is !! by default.  Only backslash (\\)
       and single quotes can quote the history expansion character.

   EEvveenntt DDeessiiggnnaattoorrss
       An event designator is a reference to a command line entry in the  his-
       tory list.

       !!      Start  a  history substitution, except when followed by a bbllaannkk,
              newline, = or (.
       !!_n     Refer to command line _n.
       !!--_n    Refer to the current command line minus _n.
       !!!!     Refer to the previous command.  This is a synonym for `!-1'.
       !!_s_t_r_i_n_g
              Refer to the most recent command starting with _s_t_r_i_n_g.
       !!??_s_t_r_i_n_g[[??]]
              Refer to the most recent command containing _s_t_r_i_n_g.  The  trail-
              ing ?? may be omitted if _s_t_r_i_n_g is followed immediately by a new-
              line.
       ^^_s_t_r_i_n_g_1^^_s_t_r_i_n_g_2^^
              Quick substitution.  Repeat the last command, replacing  _s_t_r_i_n_g_1
              with _s_t_r_i_n_g_2.  Equivalent to ``!!:s/_s_t_r_i_n_g_1/_s_t_r_i_n_g_2/'' (see MMoodd--
              iiffiieerrss below).
       !!##     The entire command line typed so far.

   WWoorrdd DDeessiiggnnaattoorrss
       Word designators are used to select desired words from the event.  A  ::
       separates  the event specification from the word designator.  It may be
       omitted if the word designator begins with a ^^, $$, **, --, or  %%.   Words
       are  numbered from the beginning of the line, with the first word being
       denoted by 0 (zero).  Words are inserted into the  current  line  sepa-
       rated by single spaces.

       00 ((zzeerroo))
              The zeroth word.  For the shell, this is the command word.
       _n      The _nth word.
       ^^      The first argument.  That is, word 1.
       $$      The last argument.
       %%      The word matched by the most recent `?_s_t_r_i_n_g?' search.
       _x--_y    A range of words; `-_y' abbreviates `0-_y'.
       **      All  of  the words but the zeroth.  This is a synonym for `_1_-_$'.
              It is not an error to use ** if there is just  one  word  in  the
              event; the empty string is returned in that case.
       xx**     Abbreviates _x_-_$.
       xx--     Abbreviates _x_-_$ like xx**, but omits the last word.

       If  a  word  designator is supplied without an event specification, the
       previous command is used as the event.

   MMooddiiffiieerrss
       After the optional word designator, there may appear a sequence of  one
       or more of the following modifiers, each preceded by a `:'.

       hh      Remove a trailing file name component, leaving only the head.
       tt      Remove all leading file name components, leaving the tail.
       rr      Remove a trailing suffix of the form _._x_x_x, leaving the basename.
       ee      Remove all but the trailing suffix.
       pp      Print the new command but do not execute it.
       qq      Quote the substituted words, escaping further substitutions.
       xx      Quote the substituted words as with qq, but break into  words  at
              bbllaannkkss and newlines.
       ss//_o_l_d//_n_e_w//
              Substitute  _n_e_w  for  the  first  occurrence of _o_l_d in the event
              line.  Any delimiter can be used  in  place  of  /.   The  final
              delimiter  is  optional if it is the last character of the event
              line.  The delimiter may be quoted in _o_l_d and _n_e_w with a  single
              backslash.   If & appears in _n_e_w, it is replaced by _o_l_d.  A sin-
              gle backslash will quote the &.  If _o_l_d is null, it  is  set  to
              the  last  _o_l_d substituted, or, if no previous history substitu-
              tions took place, the last _s_t_r_i_n_g in a !!??_s_t_r_i_n_g[[??]]  search.
       &&      Repeat the previous substitution.
       gg      Cause changes to be applied over the entire event line.  This is
              used  in  conjunction  with `::ss' (e.g., `::ggss//_o_l_d//_n_e_w//') or `::&&'.
              If used with `::ss', any delimiter can be used in place of /,  and
              the  final  delimiter is optional if it is the last character of
              the event line.  An aa may be used as a synonym for gg.
       GG      Apply the following `ss' modifier once to each word in the  event
              line.

PPRROOGGRRAAMMMMIINNGG WWIITTHH HHIISSTTOORRYY FFUUNNCCTTIIOONNSS
       This  section  describes  how  to use the History library in other pro-
       grams.

   IInnttrroodduuccttiioonn ttoo HHiissttoorryy
       The programmer using the History library has  available  functions  for
       remembering  lines on a history list, associating arbitrary data with a
       line, removing lines from the list, searching through the  list  for  a
       line  containing  an arbitrary text string, and referencing any line in
       the list directly.  In addition, a history _e_x_p_a_n_s_i_o_n function is avail-
       able  which  provides  for a consistent user interface across different
       programs.

       The user using programs written with the History library has the  bene-
       fit  of  a  consistent user interface with a set of well-known commands
       for manipulating the text of previous lines and using that text in  new
       commands.  The basic history manipulation commands are identical to the
       history substitution provided by bbaasshh.

       If the programmer desires, he  can  use  the  Readline  library,  which
       includes some history manipulation by default, and has the added advan-
       tage of command line editing.

       Before declaring any functions  using  any  functionality  the  History
       library  provides  in  other code, an application writer should include
       the file  _<_r_e_a_d_l_i_n_e_/_h_i_s_t_o_r_y_._h_>  in  any  file  that  uses  the  History
       library's  features.   It  supplies  extern declarations for all of the
       library's public functions and variables, and declares all of the  pub-
       lic data structures.


   HHiissttoorryy SSttoorraaggee
       The  history  list  is an array of history entries.  A history entry is
       declared as follows:

       _t_y_p_e_d_e_f _v_o_i_d _* hhiissttddaattaa__tt;;

       typedef struct _hist_entry {
         char *line;
         char *timestamp;
         histdata_t data;
       } HIST_ENTRY;

       The history list itself might therefore be declared as

       _H_I_S_T___E_N_T_R_Y _*_* tthhee__hhiissttoorryy__lliisstt;;

       The state of the History library is encapsulated into a  single  struc-
       ture:

       /*
        * A structure used to pass around the current state of the history.
        */
       typedef struct _hist_state {
         HIST_ENTRY **entries; /* Pointer to the entries themselves. */
         int offset;           /* The location pointer within this array. */
         int length;           /* Number of elements within this array. */
         int size;             /* Number of slots allocated to this array. */
         int flags;
       } HISTORY_STATE;

       If  the flags member includes HHSS__SSTTIIFFLLEEDD, the history has been stifled.

HHiissttoorryy FFuunnccttiioonnss
       This section describes the calling sequence for the  various  functions
       exported by the GNU History library.

   IInniittiiaalliizziinngg HHiissttoorryy aanndd SSttaattee MMaannaaggeemmeenntt
       This  section  describes  functions  used  to initialize and manage the
       state of the History library when you want to use the history functions
       in your program.

       _v_o_i_d uussiinngg__hhiissttoorryy (_v_o_i_d)
       Begin  a  session  in  which the history functions might be used.  This
       initializes the interactive variables.

       _H_I_S_T_O_R_Y___S_T_A_T_E _* hhiissttoorryy__ggeett__hhiissttoorryy__ssttaattee (_v_o_i_d)
       Return a structure describing the current state of the input history.

       _v_o_i_d hhiissttoorryy__sseett__hhiissttoorryy__ssttaattee (_H_I_S_T_O_R_Y___S_T_A_T_E _*_s_t_a_t_e)
       Set the state of the history list according to _s_t_a_t_e.


   HHiissttoorryy LLiisstt MMaannaaggeemmeenntt
       These functions manage individual entries on the history list,  or  set
       parameters managing the list itself.

       _v_o_i_d aadddd__hhiissttoorryy (_c_o_n_s_t _c_h_a_r _*_s_t_r_i_n_g)
       Place _s_t_r_i_n_g at the end of the history list.  The associated data field
       (if any) is set to NNUULLLL.

       _v_o_i_d aadddd__hhiissttoorryy__ttiimmee (_c_o_n_s_t _c_h_a_r _*_s_t_r_i_n_g)
       Change the time stamp associated with the most recent history entry  to
       _s_t_r_i_n_g.

       _H_I_S_T___E_N_T_R_Y _* rreemmoovvee__hhiissttoorryy (_i_n_t _w_h_i_c_h)
       Remove  history  entry  at  offset _w_h_i_c_h from the history.  The removed
       element is returned so you can free  the  line,  data,  and  containing
       structure.

       _h_i_s_t_d_a_t_a___t ffrreeee__hhiissttoorryy__eennttrryy (_H_I_S_T___E_N_T_R_Y _*_h_i_s_t_e_n_t)
       Free  the  history  entry  _h_i_s_t_e_n_t and any history library private data
       associated with it.   Returns  the  application-specific  data  so  the
       caller can dispose of it.

       _H_I_S_T___E_N_T_R_Y  _* rreeppllaaccee__hhiissttoorryy__eennttrryy (_i_n_t _w_h_i_c_h_, _c_o_n_s_t _c_h_a_r _*_l_i_n_e_, _h_i_s_t_-
       _d_a_t_a___t _d_a_t_a)
       Make the history entry at  offset  _w_h_i_c_h  have  _l_i_n_e  and  _d_a_t_a.   This
       returns the old entry so the caller can dispose of any application-spe-
       cific data.  In the case  of  an  invalid  _w_h_i_c_h,  a  NNUULLLL  pointer  is
       returned.

       _v_o_i_d cclleeaarr__hhiissttoorryy (_v_o_i_d)
       Clear the history list by deleting all the entries.

       _v_o_i_d ssttiiffllee__hhiissttoorryy (_i_n_t _m_a_x)
       Stifle the history list, remembering only the last _m_a_x entries.

       _i_n_t uunnssttiiffllee__hhiissttoorryy (_v_o_i_d)
       Stop  stifling  the  history.   This returns the previously-set maximum
       number of history entries (as set by  ssttiiffllee__hhiissttoorryy(())).   history  was
       stifled.  The value is positive if the history was stifled, negative if
       it wasn't.

       _i_n_t hhiissttoorryy__iiss__ssttiifflleedd (_v_o_i_d)
       Returns non-zero if the history is stifled, zero if it is not.