Man Linux: Main Page and Category List

NAME

     editline, el_init, el_end, el_reset, el_gets, el_getc, el_push, el_parse,
     el_set, 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);

     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
     libtermcap library).  Programs should be linked with -ledit -ltermcap.

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.

     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.

           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.

           EL_ADDFN, const char *name, const char *help, unsigned char
                 (*func)(EditLine *e, int ch)
                 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.

                 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 editline.  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.

           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 */
           } 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.

           H_FUNC, void *ptr, history_gfun_t first, history_gfun_t next,
                 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
                 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.

           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 if the adjacent identical event strings should not be
                 entered into the history.

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

           history() returns >= 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
           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), termcap(3), editrc(5)

HISTORY

     The editline library first appeared in 4.4BSD.  CC_REDISPLAY appeared in
     NetBSD 1.3.  CC_REFRESH_BEEP, EL_EDITMODE and the readline emulation
     appeared in NetBSD 1.4.  EL_RPROMPT appeared in NetBSD 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.