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EDITLINE(3)                Library Functions Manual                EDITLINE(3)

NAME
     editline, el_init, el_init_fd, el_end, el_reset, el_gets, el_wgets,
     el_getc, el_wgetc, el_push, el_wpush, el_parse, el_wparse, el_set,
     el_wset, el_get, el_wget, el_source, el_resize, el_cursor, el_line,
     el_wline, el_insertstr, el_winsertstr, el_deletestr, el_wdeletestr,
     history_init, history_winit, history_end, history_wend, history,
     history_w, tok_init, tok_winit, tok_end, tok_wend, tok_reset, tok_wreset,
     tok_line, tok_wline, tok_str, tok_wstr - 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);

     EditLine *
     el_init_fd(const char *prog, FILE *fin, FILE *fout, FILE *ferr, int fdin,
         int fdout, int fderr);

     void
     el_end(EditLine *e);

     void
     el_reset(EditLine *e);

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

     const wchar_t *
     el_wgets(EditLine *e, int *count);

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

     int
     el_wgetc(EditLine *e, wchar_t *wc);

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

     void
     el_wpush(EditLine *e, const wchar_t *wcs);

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

     int
     el_wparse(EditLine *e, int argc, const wchar_t *argv[]);

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

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

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

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

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

     void
     el_resize(EditLine *e);

     int
     el_cursor(EditLine *e, int count);

     const LineInfo *
     el_line(EditLine *e);

     const LineInfoW *
     el_wline(EditLine *e);

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

     int
     el_winsertstr(EditLine *e, const wchar_t *str);

     void
     el_deletestr(EditLine *e, int count);

     void
     el_wdeletestr(EditLine *e, int count);

     History *
     history_init(void);

     HistoryW *
     history_winit(void);

     void
     history_end(History *h);

     void
     history_wend(HistoryW *h);

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

     int
     history_w(HistoryW *h, HistEventW *ev, int op, ...);

     Tokenizer *
     tok_init(const char *IFS);

     TokenizerW *
     tok_winit(const wchar_t *IFS);

     void
     tok_end(Tokenizer *t);

     void
     tok_wend(TokenizerW *t);

     void
     tok_reset(Tokenizer *t);

     void
     tok_wreset(TokenizerW *t);

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

     int
     tok_wline(TokenizerW *t, const LineInfoW *li, int *argc,
         const wchar_t **argv[], int *cursorc, int *cursoro);

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

     int
     tok_wstr(TokenizerW *t, const wchar_t *str, int *argc,
         const wchar_t **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.

     The editline library respects the LC_CTYPE locale set by the application
     program and never uses setlocale(3) to change the locale.

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

     The wide-character functions behave the same way as their narrow
     counterparts.

     The following functions are available:

     el_init()
           Initialize the line editor, and return a data structure to be used
           by all other line editing functions, or NULL on failure.  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_init_fd()
           Like el_init() but allows specifying file descriptors for the
           stdio(3) corresponding streams, in case those were created with
           funopen(3).

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

     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.  If an error
           occurred, count is set to -1 and errno contains the error code that
           caused it.  The return value may not remain valid across calls to
           el_gets() and must be copied if the data is to be retained.

     el_wgetc()
           Read a wide character from the tty, respecting the current locale,
           or from the input queue described in editline(7) if that is not
           empty, and store it in wc.  If an invalid or incomplete character
           is found, it is discarded, errno is set to EILSEQ, and the next
           character is read and stored in wc.  Returns 1 if a valid character
           was read, 0 on end of file, or -1 on read(2) failure.  In the
           latter case, errno is set to indicate the error.

     el_getc()
           Read a wide character as described for el_wgetc() and return 0 on
           end of file or -1 on failure.  If the wide character can be
           represented as a single-byte character, convert it with wctob(3),
           store the result in ch, and return 1; otherwise, set errno to
           ERANGE and return -1.  In the C or POSIX locale, this simply reads
           a byte, but for any other locale, including UTF-8, this is rarely
           useful.

     el_wpush()
           Push the wide character string wcs back onto the input queue
           described in editline(7).  If the queue overflows, for example due
           to a recursive macro, or if an error occurs, for example because
           wcs is NULL or memory allocation fails, the function beeps at the
           user, but does not report the problem to the caller.

     el_push()
           Use the current locale to convert the multibyte string mbs to a
           wide character string, and pass the result to el_wpush().

     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.  Returns 0 on success,
           -1 on failure.

           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_PROMPT_ESC, char *(*f)(EditLine *), char c
                 Same as EL_PROMPT, but the c argument indicates the
                 start/stop literal prompt character.

                 If a start/stop literal character is found in the prompt, the
                 character itself is not printed, but characters after it are
                 printed directly to the terminal without affecting the state
                 of the current line.  A subsequent second start/stop literal
                 character ends this behavior.  This is typically used to
                 embed literal escape sequences that change the color/style of
                 the terminal in the prompt.  Note that the literal escape
                 character cannot be the last character in the prompt, as the
                 escape sequence is attached to the next character in the
                 prompt.  0 unsets it.

           EL_REFRESH
                 Re-display the current line on the next terminal line.

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

           EL_RPROMPT_ESC, char *(*f)(EditLine *), char c
                 Define the right prompt printing function but with a literal
                 escape character.

           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_UNBUFFERED, int flag
                 If flag is zero, unbuffered mode is disabled (the default).
                 In unbuffered mode, el_gets() will return immediately after
                 processing a single character.

           EL_SAFEREAD, int flag
                 If the flag argument is non-zero, then editline attempts to
                 recover from read errors, ignoring the first interrrupted
                 error, and trying to reset the input file descriptor to reset
                 non-blocking I/O.  This is disabled by default, and desirable
                 only when editline is used in shell-like applications.

           EL_GETCFN, el_rfunc_t f
                 Whenever reading a character, use the function
                       int f(EditLine *e, wchar_t *wc)
                 which stores the character in wc and returns 1 on success, 0
                 on end of file, or -1 on I/O or encoding errors.  Functions
                 internally using it include el_wgets(), el_wgetc(),
                 el_gets(), and el_getc().  Initially, a builtin function is
                 installed, and replacing it is discouraged because writing
                 such a function is very error prone.  The builtin function
                 can be restored at any time by passing the special value
                 EL_BUILTIN_GETCFN instead of a function pointer.

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

           EL_SETFP, int fd, FILE *fp
                 Set the current editline file pointer for "input" fd = 0,
                 "output" fd = 1, or "error" fd = 2 from fp.

     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 *), char *c
                 Set f to a pointer to the function that displays the prompt.
                 If c is not NULL, set it to the start/stop literal prompt
                 character.

           EL_RPROMPT, char *(*f)(EditLine *), char *c
                 Set f to a pointer to the function that displays the prompt.
                 If c is not NULL, set it to the start/stop literal prompt
                 character.

           EL_EDITOR, const char **n
                 Set the name of the editor in n, which will be one of "emacs"
                 or "vi".

           EL_GETTC, const char *name, void *value
                 If name is a valid termcap(5) capability set value to the
                 current value of that capability.

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

           EL_EDITMODE, int *c
                 Set c to non-zero if editing is enabled.

           EL_GETCFN, el_rfunc_t *f
                 Set f to a pointer to the function that reads characters, or
                 to EL_BUILTIN_GETCFN if the builtin function is in use.

           EL_CLIENTDATA, void **data
                 Set data to the previously registered client data set by an
                 el_set() call.

           EL_UNBUFFERED, int *c
                 Set c to non-zero if unbuffered mode is enabled.

           EL_SAFEREAD, int *c
                 Set c to non-zero if safe read is set.

           EL_GETFP, int fd, FILE **fp
                 Set fp to the current editline file pointer for "input" fd =
                 0, "output" fd = 1, or "error" fd = 2.

     el_source()
           Initialize editline by reading the contents of file.  el_parse() is
           called for each line in file.  If file is NULL, try $EDITRC and if
           that is not set $HOME/.editrc.  Refer to editrc(5) for details on
           the format of file.  el_source() returns 0 on success and -1 on
           error.

     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_cursor()
           Move the cursor to the right (if positive) or to the left (if
           negative) count characters.  Returns the resulting offset of the
           cursor from the beginning of the line.

     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 count 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()
           Initialize the history list, and return a data structure to be used
           by all other history list functions, or NULL on failure.

     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.  It is newer than
                 the current one.

           H_NEXT
                 Return the next element in the history.  It is older than the
                 current one.

           H_CURR
                 Return the current element in the history.

           H_SET, int position
                 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 has been called with a non-zero
                 argument, 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_SAVE_FP, FILE *fp
                 Save the history list to the opened FILE pointer fp.

           H_NSAVE_FP, size_t n, FILE *fp
                 Save the last n history entries to the opened FILE pointer
                 fp.

           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 e
                 Delete the event numbered e.  This function is only provided
                 for readline compatibility.  The caller is responsible for
                 free'ing the string in the returned HistEvent.

           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()
           Initialize 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), termcap(5), editline(7)

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.
     Johny Mattsson implemented wide-character support.

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.

NetBSD 10.99                    August 15, 2021                   NetBSD 10.99