NAME
editline
, el_init
,
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_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
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);
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);
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
libcurses
library). Programs should be linked with
-ledit
-lcurses
.
The editline
library is
designed to work with blocking I/O only. If the
FIONBIO
ioctl(2) or the O_NONBLOCK
fcntl(2) is set on
fin,
el_gets
()
and
el_wgets
()
will almost certainly fail with EAGAIN.
The editline
library respects the
LC_CTYPE
locale set by the application program and
never uses setlocale(3)
to change the locale. The only locales supported are UTF-8 and the default C
or POSIX locale. If any other locale is set, behaviour is undefined.
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 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_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. If an error occurred, count is set to -1 anderrno
contains the error code that caused it. The return value may not remain valid across calls toel_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 toERANGE
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”: thenel_parse
() will only execute the command if “prog” matches the prog argument supplied toel_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.
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 isNULL
. 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
, andSIGWINCH
. 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 offunc
() 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 byhistory_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 (usingel_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_GETCFN
, el_rfunc_t f- Whenever reading a character, use the function
intwhich 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
f
(EditLine *e, wchar_t *wc);el_wgets
(),el_wgetc
(),el_gets
(), andel_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 valueEL_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 (seeel_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_PREP_TERM
, int- Sets or clears terminal editing mode.
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 isNULL
, try $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 withel_set
(), then this is done automatically. Otherwise, it's the responsibility of the application to callel_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 withEL_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
- 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. Finallyhistory
() 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_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(3) 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
() ortok_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 notNULL
) 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), curses(3), signal(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.