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     NAME
          editline, el_init, el_end, el_reset, el_gets, el_getc, el_push,
          el_parse, el_set, el_get, el_source, el_resize, el_line, el_insertstr,
          el_deletestr, history_init, history_end, history, tok_init, tok_end,
          tok_reset, tok_line, tok_str - line editor, history and tokenization
          functions

     LIBRARY
          Command Line Editor Library (libedit, -ledit)

     SYNOPSIS
          #include <histedit.h>

          EditLine *
          el_init(const char *prog, FILE *fin, FILE *fout, FILE *ferr);

          void
          el_end(EditLine *e);

          void
          el_reset(EditLine *e);

          const char *
          el_gets(EditLine *e, int *count);

          int
          el_getc(EditLine *e, char *ch);

          void
          el_push(EditLine *e, const char *str);

          int
          el_parse(EditLine *e, int argc, const char *argv[]);

          int
          el_set(EditLine *e, int op, ...);

          int
          el_get(EditLine *e, int op, void *result);

          int
          el_source(EditLine *e, const char *file);

          void
          el_resize(EditLine *e);

          const LineInfo *
          el_line(EditLine *e);

          int
          el_insertstr(EditLine *e, const char *str);

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          void
          el_deletestr(EditLine *e, int count);

          History *
          history_init();

          void
          history_end(History *h);

          int
          history(History *h, HistEvent *ev, int op, ...);

          Tokenizer *
          tok_init(const char *IFS);

          void
          tok_end(Tokenizer *t);

          void
          tok_reset(Tokenizer *t);

          int
          tok_line(Tokenizer *t, const LineInfo *li, int *argc, const char
          **argv[], int *cursorc, int *cursoro);

          int
          tok_str(Tokenizer *t, const char *str, int *argc, const char **argv[]);

     DESCRIPTION
          The editline library provides generic line editing, history and
          tokenization functions, similar to those found in sh(1).

          These functions are available in the libedit library (which needs the
          libcurses library).  Programs should be linked with -ledit -lcurses.

     LINE EDITING FUNCTIONS
          The line editing functions use a common data structure, EditLine,
          which is created by el_init() and freed by el_end().

          The following functions are available:

          el_init()
               Initialise the line editor, and return a data structure to be
               used by all other line editing functions.  prog is the name of
               the invoking program, used when reading the editrc(5) file to
               determine which settings to use.  fin, fout and ferr are the
               input, output, and error streams (respectively) to use.  In this
               documentation, references to ``the tty'' are actually to this
               input/output stream combination.

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          el_end()
               Clean up and finish with e, assumed to have been created with
               el_init().

          el_reset()
               Reset the tty and the parser.  This should be called after an
               error which may have upset the tty's state.

          el_gets()
               Read a line from the tty.  count is modified to contain the
               number of characters read.  Returns the line read if successful,
               or NULL if no characters were read or if an error occurred.

          el_getc()
               Read a character from the tty.  ch is modified to contain the
               character read.  Returns the number of characters read if
               successful, -1 otherwise.

          el_push()
               Pushes str back onto the input stream.  This is used by the macro
               expansion mechanism.  Refer to the description of bind -s in
               editrc(5) for more information.

          el_parse()
               Parses the argv array (which is argc elements in size) to execute
               builtin editline commands.  If the command is prefixed with
               ``prog :'' then el_parse() will only execute the command if
               ``prog'' matches the prog argument supplied to el_init().  The
               return value is -1 if the command is unknown, 0 if there was no
               error or ``prog'' didn't match, or 1 if the command returned an
               error.  Refer to editrc(5) for more information.

          el_set()
               Set editline parameters.  op determines which parameter to set,
               and each operation has its own parameter list.

               The following values for op are supported, along with the
               required argument list:

               EL_PROMPT , char *(*f)(EditLine *)
                    Define prompt printing function as f, which is to return a
                    string that contains the prompt.

               EL_RPROMPT , char *(*f)(EditLine *)
                    Define right side prompt printing function as f, which is to
                    return a string that contains the prompt.

               EL_TERMINAL , const char *type
                    Define terminal type of the tty to be type, or to TERM if
                    type is NULL .

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               EL_EDITOR , const char *mode
                    Set editing mode to mode, which must be one of ``emacs'' or
                    ``vi''.

               EL_SIGNAL , int flag
                    If flag is non-zero, editline will install its own signal
                    handler for the following signals when reading command
                    input: SIGCONT , SIGHUP , SIGINT , SIGQUIT , SIGSTOP ,
                    SIGTERM , SIGTSTP , and SIGWINCH .  Otherwise, the current
                    signal handlers will be used.

               EL_BIND , const char *, ..., NULL
                    Perform the bind builtin command.  Refer to editrc(5) for
                    more information.

               EL_ECHOTC , const char *, ..., NULL
                    Perform the echotc builtin command.  Refer to editrc(5) for
                    more information.

               EL_SETTC , const char *, ..., NULL
                    Perform the settc builtin command.  Refer to editrc(5) for
                    more information.

               EL_SETTY , const char *, ..., NULL
                    Perform the setty builtin command.  Refer to editrc(5) for
                    more information.

               EL_TELLTC , const char *, ..., NULL
                    Perform the telltc builtin command.  Refer to editrc(5) for
                    more information.

               (*func)(EditLine *e, int ch)
               EL_ADDFN , const char *name, const char *help, unsigned char
                    Add a user defined function, func(), referred to as name
                    which is invoked when a key which is bound to name is
                    entered.  help is a description of name.  At invocation
                    time, ch is the key which caused the invocation.  The return
                    value of func() should be one of:

                    CC_NORM
                         Add a normal character.

                    CC_NEWLINE
                         End of line was entered.

                    CC_EOF
                         EOF was entered.

                    CC_ARGHACK
                         Expecting further command input as arguments, do
                         nothing visually.

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                    CC_REFRESH
                         Refresh display.

                    CC_REFRESH_BEEP
                         Refresh display, and beep.

                    CC_CURSOR
                         Cursor moved, so update and perform CC_REFRESH .

                    CC_REDISPLAY
                         Redisplay entire input line.  This is useful if a key
                         binding outputs extra information.

                    CC_ERROR
                         An error occurred.  Beep, and flush tty.

                    CC_FATAL
                         Fatal error, reset tty to known state.

               EL_HIST , History *(*func)(History *, int op, ...), const char *ptr
                    Defines which history function to use, which is usually
                    history().  ptr should be the value returned by
                    history_init().

               EL_EDITMODE , int flag
                    If flag is non-zero, editing is enabled (the default).  Note
                    that this is only an indication, and does not affect the
                    operation of At this time, it is the caller's responsibility
                    to check this (using el_get() ) to determine if editing
                    should be enabled or not.

               EL_GETCFN , int (*f)(EditLine *, char *c)
                    Define the character reading function as f, which is to
                    return the number of characters read and store them in c.
                    This function is called internally by el_gets() and
                    el_getc().  The builtin function can be set or restored with
                    the special function name ``EL_BUILTIN_GETCFN''.

               EL_CLIENTDATA , void *data
                    Register data to be associated with this EditLine structure.
                    It can be retrieved with the corresponding el_get() call.

          el_get()
               Get editline parameters.  op determines which parameter to
               retrieve into result.  Returns 0 if successful, -1 otherwise.

               The following values for op are supported, along with actual type
               of result :

               EL_PROMPT , char *(*f)(EditLine *)
                    Return a pointer to the function that displays the prompt.

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               EL_RPROMPT , char *(*f)(EditLine *)
                    Return a pointer to the function that displays the rightside
                    prompt.

               EL_EDITOR , const char *
                    Return the name of the editor, which will be one of
                    ``emacs'' or ``vi''.

               EL_SIGNAL , int *
                    Return non-zero if editline has installed private signal
                    handlers (see el_get() above).

               EL_EDITMODE, int *
                    Return non-zero if editing is enabled.

               EL_GETCFN, int (**f)(EditLine *, char *)
                    Return a pointer to the function that read characters, which
                    is equal to ``EL_BUILTIN_GETCFN'' in the case of the default
                    builtin function.

               EL_CLIENTDATA , void **data
                    Retrieve data previously registered with the corresponding
                    el_set() call.

               EL_UNBUFFERED, int
                    Sets or clears unbuffered mode.  In this mode, el_gets()
                    will return immediately after processing a single character.

               EL_PREP_TERM, int
                    Sets or clears terminal editing mode.

          el_source()
               Initialise editline by reading the contents of file.  el_parse()
               is called for each line in file.  If file is NULL , try
               $PWD/.editrc then $HOME/.editrc.  Refer to editrc(5) for details
               on the format of file.

          el_resize()
               Must be called if the terminal size changes.  If EL_SIGNAL has
               been set with el_set(), then this is done automatically.
               Otherwise, it's the responsibility of the application to call
               el_resize() on the appropriate occasions.

          el_line()
               Return the editing information for the current line in a LineInfo
               structure, which is defined as follows:

               typedef struct lineinfo {
                   const char *buffer;    /* address of buffer */
                   const char *cursor;    /* address of cursor */
                   const char *lastchar;  /* address of last character */

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               } LineInfo;

               buffer is not NUL terminated.  This function may be called after
               el_gets() to obtain the LineInfo structure pertaining to line
               returned by that function, and from within user defined functions
               added with EL_ADDFN .

          el_insertstr()
               Insert str into the line at the cursor.  Returns -1 if str is
               empty or won't fit, and 0 otherwise.

          el_deletestr()
               Delete num characters before the cursor.

     HISTORY LIST FUNCTIONS
          The history functions use a common data structure, History, which is
          created by history_init() and freed by history_end().

          The following functions are available:

          history_init()
               Initialise the history list, and return a data structure to be
               used by all other history list functions.

          history_end()
               Clean up and finish with h, assumed to have been created with
               history_init().

          history()
               Perform operation op on the history list, with optional arguments
               as needed by the operation.  ev is changed accordingly to
               operation.  The following values for op are supported, along with
               the required argument list:

               H_SETSIZE , int size
                    Set size of history to size elements.

               H_GETSIZE
                    Get number of events currently in history.

               H_END
                    Cleans up and finishes with h, assumed to be created with
                    history_init().

               H_CLEAR
                    Clear the history.

               history_gfun_t last, history_gfun_t prev, history_gfun_t curr,
               history_sfun_t set, history_vfun_t clear, history_efun_t enter,
               history_efun_t add
               H_FUNC , void *ptr, history_gfun_t first, history_gfun_t next,

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                    Define functions to perform various history operations.  ptr
                    is the argument given to a function when it's invoked.

               H_FIRST
                    Return the first element in the history.

               H_LAST
                    Return the last element in the history.

               H_PREV
                    Return the previous element in the history.

               H_NEXT
                    Return the next element in the history.

               H_CURR
                    Return the current element in the history.

               H_SET
                    Set the cursor to point to the requested element.

               H_ADD , const char *str
                    Append str to the current element of the history, or perform
                    the H_ENTER operation with argument str if there is no
                    current element.

               H_APPEND , const char *str
                    Append str to the last new element of the history.

               H_ENTER , const char *str
                    Add str as a new element to the history, and, if necessary,
                    removing the oldest entry to keep the list to the created
                    size.  If H_SETUNIQUE was has been called with a non-zero
                    arguments, the element will not be entered into the history
                    if its contents match the ones of the current history
                    element.  If the element is entered history() returns 1, if
                    it is ignored as a duplicate returns 0.  Finally history()
                    returns -1 if an error occurred.

               H_PREV_STR , const char *str
                    Return the closest previous event that starts with str.

               H_NEXT_STR , const char *str
                    Return the closest next event that starts with str.

               H_PREV_EVENT , int e
                    Return the previous event numbered e.

               H_NEXT_EVENT , int e
                    Return the next event numbered e.

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               H_LOAD , const char *file
                    Load the history list stored in file.

               H_SAVE , const char *file
                    Save the history list to file.

               H_SETUNIQUE , int unique
                    Set flag that adjacent identical event strings should not be
                    entered into the history.

               H_GETUNIQUE
                    Retrieve the current setting if adjacent identical elements
                    should be entered into the history.

               H_DEL , int num
                    Delete the event numbered e.  This function is only provided
                    for readline(3) compatibility.  The caller is responsible
                    for free'ing the string in the returned HistEvent.

          history() returns Gt]= 0 if the operation op succeeds.  Otherwise, -1
          is returned and ev is updated to contain more details about the error.

     TOKENIZATION FUNCTIONS
          The tokenization functions use a common data structure, Tokenizer,
          which is created by tok_init() and freed by tok_end().

          The following functions are available:

          tok_init()
               Initialise the tokenizer, and return a data structure to be used
               by all other tokenizer functions.  IFS contains the Input Field
               Separators, which defaults to <space> , <tab> , and <newline> if
               NULL .

          tok_end()
               Clean up and finish with t, assumed to have been created with
               tok_init().

          tok_reset()
               Reset the tokenizer state.  Use after a line has been
               successfully tokenized by tok_line() or tok_str() and before a
               new line is to be tokenized.

          tok_line()
               Tokenize li, If successful, modify: argv to contain the words,
               argc to contain the number of words, cursorc (if not NULL ) to
               contain the index of the word containing the cursor, and cursoro
               (if not NULL ) to contain the offset within argv[cursorc] of the
               cursor.

               Returns 0 if successful, -1 for an internal error, 1 for an

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               unmatched single quote, 2 for an unmatched double quote, and 3
               for a backslash quoted <newline .> A positive exit code indicates
               that another line should be read and tokenization attempted
               again.

          tok_str()
               A simpler form of tok_line(; ) str is a NUL terminated string to
               tokenize.

     SEE ALSO
          sh(1), signal(3), curses(3), editrc(5)

     HISTORY
          The editline library first appeared in Bx 4.4 .  CC_REDISPLAY appeared
          in Nx 1.3 .  CC_REFRESH_BEEP , EL_EDITMODE and the readline emulation
          appeared in Nx 1.4 .  EL_RPROMPT appeared in Nx 1.5 .

     AUTHORS
          The editline library was written by Christos Zoulas.  Luke Mewburn
          wrote this manual and implemented CC_REDISPLAY , CC_REFRESH_BEEP ,
          EL_EDITMODE , and EL_RPROMPT .  Jaromir Dolecek implemented the
          readline emulation.

     BUGS
          At this time, it is the responsibility of the caller to check the
          result of the EL_EDITMODE operation of el_get() (after an el_source()
          or el_parse() ) to determine if editline should be used for further
          input.  I.e., EL_EDITMODE is purely an indication of the result of the
          most recent editrc(5) edit command.

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