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EDITLINE(3) FreeBSD 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
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
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
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
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.
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.
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 */
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
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
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.
FreeBSD 14.0-RELEASE-p11 August 15, 2021 FreeBSD 14.0-RELEASE-p11