Provided by: libedit-dev_3.1-20230828-1build1_amd64 
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(5edit), termcap(5), editline(7edit)
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.