path: root/bin/cash/libedit/editline.3

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.Dd June 27, 2017
.Dt EDITLINE 3
.Os
.Sh NAME
.Nm editline ,
.Nm el_init ,
.Nm el_init_fd ,
.Nm el_end ,
.Nm el_reset ,
.Nm el_gets ,
.Nm el_wgets ,
.Nm el_getc ,
.Nm el_wgetc ,
.Nm el_push ,
.Nm el_wpush ,
.Nm el_parse ,
.Nm el_wparse ,
.Nm el_set ,
.Nm el_wset ,
.Nm el_get ,
.Nm el_wget ,
.Nm el_source ,
.Nm el_resize ,
.Nm el_cursor ,
.Nm el_line ,
.Nm el_wline ,
.Nm el_insertstr ,
.Nm el_winsertstr ,
.Nm el_deletestr ,
.Nm el_wdeletestr ,
.Nm history_init ,
.Nm history_winit ,
.Nm history_end ,
.Nm history_wend ,
.Nm history ,
.Nm history_w ,
.Nm tok_init ,
.Nm tok_winit ,
.Nm tok_end ,
.Nm tok_wend ,
.Nm tok_reset ,
.Nm tok_wreset ,
.Nm tok_line ,
.Nm tok_wline ,
.Nm tok_str ,
.Nm tok_wstr
.Nd line editor, history and tokenization functions
.Sh LIBRARY
.Lb libedit
.Sh SYNOPSIS
.In histedit.h
.Ft EditLine *
.Fn el_init "const char *prog" "FILE *fin" "FILE *fout" "FILE *ferr"
.Ft EditLine *
.Fn el_init_fd "const char *prog" "FILE *fin" "FILE *fout" "FILE *ferr" "int fdin" "int fdout" "int fderr"
.Ft void
.Fn el_end "EditLine *e"
.Ft void
.Fn el_reset "EditLine *e"
.Ft const char *
.Fn el_gets "EditLine *e" "int *count"
.Ft const wchar_t *
.Fn el_wgets "EditLine *e" "int *count"
.Ft int
.Fn el_getc "EditLine *e" "char *ch"
.Ft int
.Fn el_wgetc "EditLine *e" "wchar_t *wc"
.Ft void
.Fn el_push "EditLine *e" "const char *mbs"
.Ft void
.Fn el_wpush "EditLine *e" "const wchar_t *wcs"
.Ft int
.Fn el_parse "EditLine *e" "int argc" "const char *argv[]"
.Ft int
.Fn el_wparse "EditLine *e" "int argc" "const wchar_t *argv[]"
.Ft int
.Fn el_set "EditLine *e" "int op" "..."
.Ft int
.Fn el_wset "EditLine *e" "int op" "..."
.Ft int
.Fn el_get "EditLine *e" "int op" "..."
.Ft int
.Fn el_wget "EditLine *e" "int op" "..."
.Ft int
.Fn el_source "EditLine *e" "const char *file"
.Ft void
.Fn el_resize "EditLine *e"
.Ft int
.Fn el_cursor "EditLine *e" "int count"
.Ft const LineInfo *
.Fn el_line "EditLine *e"
.Ft const LineInfoW *
.Fn el_wline "EditLine *e"
.Ft int
.Fn el_insertstr "EditLine *e" "const char *str"
.Ft int
.Fn el_winsertstr "EditLine *e" "const wchar_t *str"
.Ft void
.Fn el_deletestr "EditLine *e" "int count"
.Ft void
.Fn el_wdeletestr "EditLine *e" "int count"
.Ft History *
.Fn history_init void
.Ft HistoryW *
.Fn history_winit void
.Ft void
.Fn history_end "History *h"
.Ft void
.Fn history_wend "HistoryW *h"
.Ft int
.Fn history "History *h" "HistEvent *ev" "int op" "..."
.Ft int
.Fn history_w "HistoryW *h" "HistEventW *ev" "int op" "..."
.Ft Tokenizer *
.Fn tok_init "const char *IFS"
.Ft TokenizerW *
.Fn tok_winit "const wchar_t *IFS"
.Ft void
.Fn tok_end "Tokenizer *t"
.Ft void
.Fn tok_wend "TokenizerW *t"
.Ft void
.Fn tok_reset "Tokenizer *t"
.Ft void
.Fn tok_wreset "TokenizerW *t"
.Ft int
.Fn tok_line "Tokenizer *t" "const LineInfo *li" "int *argc" "const char **argv[]" "int *cursorc" "int *cursoro"
.Ft int
.Fn tok_wline "TokenizerW *t" "const LineInfoW *li" "int *argc" "const wchar_t **argv[]" "int *cursorc" "int *cursoro"
.Ft int
.Fn tok_str "Tokenizer *t" "const char *str" "int *argc" "const char **argv[]"
.Ft int
.Fn tok_wstr "TokenizerW *t" "const wchar_t *str" "int *argc" "const wchar_t **argv[]"
.Sh DESCRIPTION
The
.Nm
library provides generic line editing, history and tokenization functions,
similar to those found in
.Xr sh 1 .
.Pp
These functions are available in the
.Nm libedit
library (which needs the
.Nm libtermcap
library).
Programs should be linked with
.Fl ledit ltermcap .
.Pp
The
.Nm
library respects the
.Ev LC_CTYPE
locale set by the application program and never uses
.Xr 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.
.Sh LINE EDITING FUNCTIONS
The line editing functions use a common data structure,
.Fa EditLine ,
which is created by
.Fn el_init
or
.Fn el_init_fd
and freed by
.Fn el_end .
.Pp
The wide-character functions behave the same way as their narrow
counterparts.
.Pp
The following functions are available:
.Bl -tag -width 4n
.It Fn el_init
Initialize the line editor, and return a data structure
to be used by all other line editing functions, or
.Dv NULL
on failure.
.Fa prog
is the name of the invoking program, used when reading the
.Xr editrc 5
file to determine which settings to use.
.Fa fin ,
.Fa fout
and
.Fa ferr
are the input, output, and error streams (respectively) to use.
In this documentation, references to
.Dq the tty
are actually to this input/output stream combination.
.It Fn el_init_fd
Like
.Fn el_init
but allows specifying file descriptors for the
.Xr stdio 3
corresponding streams, in case those were created with
.Xr funopen 3 .
.It Fn el_end
Clean up and finish with
.Fa e ,
assumed to have been created with
.Fn el_init
or
.Fn el_init_fd .
.It Fn el_reset
Reset the tty and the parser.
This should be called after an error which may have upset the tty's
state.
.It Fn el_gets
Read a line from the tty.
.Fa count
is modified to contain the number of characters read.
Returns the line read if successful, or
.Dv NULL
if no characters were read or if an error occurred.
If an error occurred,
.Fa count
is set to \-1 and
.Dv errno
contains the error code that caused it.
The return value may not remain valid across calls to
.Fn el_gets
and must be copied if the data is to be retained.
.It Fn el_wgetc
Read a wide character from the tty, respecting the current locale,
or from the input queue described in
.Xr editline 7
if that is not empty, and store it in
.Fa wc .
If an invalid or incomplete character is found, it is discarded,
.Va errno
is set to
.Er EILSEQ ,
and the next character is read and stored in
.Fa wc .
Returns 1 if a valid character was read, 0 on end of file, or \-1 on
.Xr read 2
failure.
In the latter case,
.Va errno
is set to indicate the error.
.It Fn el_getc
Read a wide character as described for
.Fn 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
.Xr wctob 3 ,
store the result in
.Fa ch ,
and return 1; otherwise, set
.Va errno
to
.Er 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.
.It Fn el_wpush
Push the wide character string
.Fa wcs
back onto the input queue described in
.Xr editline 7 .
If the queue overflows, for example due to a recursive macro,
or if an error occurs, for example because
.Fa wcs
is
.Dv NULL
or memory allocation fails, the function beeps at the user,
but does not report the problem to the caller.
.It Fn el_push
Use the current locale to convert the multibyte string
.Fa mbs
to a wide character string, and pass the result to
.Fn el_wpush .
.It Fn el_parse
Parses the
.Fa argv
array (which is
.Fa argc
elements in size)
to execute builtin
.Nm
commands.
If the command is prefixed with
.Dq prog :
then
.Fn el_parse
will only execute the command if
.Dq prog
matches the
.Fa prog
argument supplied to
.Fn el_init .
The return value is
\-1 if the command is unknown,
0 if there was no error or
.Dq prog
didn't match, or
1 if the command returned an error.
Refer to
.Xr editrc 5
for more information.
.It Fn el_set
Set
.Nm
parameters.
.Fa op
determines which parameter to set, and each operation has its
own parameter list.
Returns 0 on success, \-1 on failure.
.Pp
The following values for
.Fa op
are supported, along with the required argument list:
.Bl -tag -width 4n
.It Dv EL_PROMPT , Fa "char *(*f)(EditLine *)"
Define prompt printing function as
.Fa f ,
which is to return a string that contains the prompt.
.It Dv EL_PROMPT_ESC , Fa "char *(*f)(EditLine *)" , Fa "char c"
Same as
.Dv EL_PROMPT ,
but the
.Fa c
argument indicates the start/stop literal prompt character.
.Pp
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.
.Dv 0
unsets it.
.It Dv EL_REFRESH
Re-display the current line on the next terminal line.
.It Dv EL_RPROMPT , Fa "char *(*f)(EditLine *)"
Define right side prompt printing function as
.Fa f ,
which is to return a string that contains the prompt.
.It Dv EL_RPROMPT_ESC , Fa "char *(*f)(EditLine *)" , Fa "char c"
Define the right prompt printing function but with a literal escape character.
.It Dv EL_TERMINAL , Fa "const char *type"
Define terminal type of the tty to be
.Fa type ,
or to
.Ev TERM
if
.Fa type
is
.Dv NULL .
.It Dv EL_EDITOR , Fa "const char *mode"
Set editing mode to
.Fa mode ,
which must be one of
.Dq emacs
or
.Dq vi .
.It Dv EL_SIGNAL , Fa "int flag"
If
.Fa flag
is non-zero,
.Nm
will install its own signal handler for the following signals when
reading command input:
.Dv SIGCONT ,
.Dv SIGHUP ,
.Dv SIGINT ,
.Dv SIGQUIT ,
.Dv SIGSTOP ,
.Dv SIGTERM ,
.Dv SIGTSTP ,
and
.Dv SIGWINCH .
Otherwise, the current signal handlers will be used.
.It Dv EL_BIND , Fa "const char *" , Fa "..." , Dv NULL
Perform the
.Ic bind
builtin command.
Refer to
.Xr editrc 5
for more information.
.It Dv EL_ECHOTC , Fa "const char *" , Fa "..." , Dv NULL
Perform the
.Ic echotc
builtin command.
Refer to
.Xr editrc 5
for more information.
.It Dv EL_SETTC , Fa "const char *" , Fa "..." , Dv NULL
Perform the
.Ic settc
builtin command.
Refer to
.Xr editrc 5
for more information.
.It Dv EL_SETTY , Fa "const char *" , Fa "..." , Dv NULL
Perform the
.Ic setty
builtin command.
Refer to
.Xr editrc 5
for more information.
.It Dv EL_TELLTC , Fa "const char *" , Fa "..." , Dv NULL
Perform the
.Ic telltc
builtin command.
Refer to
.Xr editrc 5
for more information.
.It Dv EL_ADDFN , Fa "const char *name" , Fa "const char *help" , \
Fa "unsigned char (*func)(EditLine *e, int ch)"
Add a user defined function,
.Fn func ,
referred to as
.Fa name
which is invoked when a key which is bound to
.Fa name
is entered.
.Fa help
is a description of
.Fa name .
At invocation time,
.Fa ch
is the key which caused the invocation.
The return value of
.Fn func
should be one of:
.Bl -tag -width "CC_REDISPLAY"
.It Dv CC_NORM
Add a normal character.
.It Dv CC_NEWLINE
End of line was entered.
.It Dv CC_EOF
EOF was entered.
.It Dv CC_ARGHACK
Expecting further command input as arguments, do nothing visually.
.It Dv CC_REFRESH
Refresh display.
.It Dv CC_REFRESH_BEEP
Refresh display, and beep.
.It Dv CC_CURSOR
Cursor moved, so update and perform
.Dv CC_REFRESH .
.It Dv CC_REDISPLAY
Redisplay entire input line.
This is useful if a key binding outputs extra information.
.It Dv CC_ERROR
An error occurred.
Beep, and flush tty.
.It Dv CC_FATAL
Fatal error, reset tty to known state.
.El
.It Dv EL_HIST , Fa "History *(*func)(History *, int op, ...)" , \
Fa "const char *ptr"
Defines which history function to use, which is usually
.Fn history .
.Fa ptr
should be the value returned by
.Fn history_init .
.It Dv EL_EDITMODE , Fa "int flag"
If
.Fa flag
is non-zero,
editing is enabled (the default).
Note that this is only an indication, and does not
affect the operation of
.Nm .
At this time, it is the caller's responsibility to
check this
(using
.Fn el_get )
to determine if editing should be enabled or not.
.It Dv EL_UNBUFFERED , Fa "int flag"
If
.Fa flag
is zero,
unbuffered mode is disabled (the default).
In unbuffered mode,
.Fn el_gets
will return immediately after processing a single character.
.It Dv EL_GETCFN , Fa "el_rfunc_t f"
Whenever reading a character, use the function
.Bd -ragged -offset indent -compact
.Ft int
.Fo f
.Fa "EditLine *e"
.Fa "wchar_t *wc"
.Fc
.Ed
which stores the character in
.Fa wc
and returns 1 on success, 0 on end of file, or \-1 on I/O or encoding
errors.
Functions internally using it include
.Fn el_wgets ,
.Fn el_wgetc ,
.Fn el_gets ,
and
.Fn 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
.Dv EL_BUILTIN_GETCFN
instead of a function pointer.
.It Dv EL_CLIENTDATA , Fa "void *data"
Register
.Fa data
to be associated with this EditLine structure.
It can be retrieved with the corresponding
.Fn el_get
call.
.It Dv EL_SETFP , Fa "int fd" , Fa "FILE *fp"
Set the current
.Nm editline
file pointer for
.Dq input
.Fa fd
=
.Dv 0 ,
.Dq output
.Fa fd
=
.Dv 1 ,
or
.Dq error
.Fa fd
=
.Dv 2
from
.Fa fp .
.El
.It Fn el_get
Get
.Nm
parameters.
.Fa op
determines which parameter to retrieve into
.Fa result .
Returns 0 if successful, \-1 otherwise.
.Pp
The following values for
.Fa op
are supported, along with actual type of
.Fa result :
.Bl -tag -width 4n
.It Dv EL_PROMPT , Fa "char *(*f)(EditLine *)" , Fa "char *c"
Set
.Fa f
to a pointer to the function that displays the prompt.
If
.Fa c
is not
.Dv NULL ,
set it to the start/stop literal prompt character.
.It Dv EL_RPROMPT , Fa "char *(*f)(EditLine *)" , Fa "char *c"
Set
.Fa f
to a pointer to the function that displays the prompt.
If
.Fa c
is not
.Dv NULL ,
set it to the start/stop literal prompt character.
.It Dv EL_EDITOR , Fa "const char **n"
Set the name of the editor in
.Fa n ,
which will be one of
.Dq emacs
or
.Dq vi .
.It Dv EL_GETTC , Fa "const char *name" , Fa "void *value"
If
.Fa name
is a valid
.Xr termcap 5
capability set
.Fa value
to the current value of that capability.
.It Dv EL_SIGNAL , Fa "int *s"
Set
.Fa s
to non-zero if
.Nm
has installed private signal handlers (see
.Fn el_get
above).
.It Dv EL_EDITMODE , Fa "int *c"
Set
.Fa c
to non-zero if editing is enabled.
.It Dv EL_GETCFN , Fa "el_rfunc_t *f"
Set
.Fa f
to a pointer to the function that reads characters, or to
.Dv EL_BUILTIN_GETCFN
if the builtin function is in use.
.It Dv EL_CLIENTDATA , Fa "void **data"
Set
.Fa data
to the previously registered client data set by an
.Fn el_set
call.
.It Dv EL_UNBUFFERED , Fa "int *c"
Set
.Fa c
to non-zero if unbuffered mode is enabled.
.It Dv EL_GETFP , Fa "int fd", Fa "FILE **fp"
Set
.Fa fp
to the current
.Nm editline
file pointer for
.Dq input
.Fa fd
=
.Dv 0 ,
.Dq output
.Fa fd
=
.Dv 1 ,
or
.Dq error
.Fa fd
=
.Dv 2 .
.El
.It Fn el_source
Initialize
.Nm
by reading the contents of
.Fa file .
.Fn el_parse
is called for each line in
.Fa file .
If
.Fa file
is
.Dv NULL ,
try
.Pa $EDITRC
and if that is not set
.Pa $HOME/.editrc .
Refer to
.Xr editrc 5
for details on the format of
.Fa file .
.Fn el_source
returns 0 on success and \-1 on error.
.It Fn el_resize
Must be called if the terminal size changes.
If
.Dv EL_SIGNAL
has been set with
.Fn el_set ,
then this is done automatically.
Otherwise, it's the responsibility of the application to call
.Fn el_resize
on the appropriate occasions.
.It Fn el_cursor
Move the cursor to the right (if positive) or to the left (if negative)
.Fa count
characters.
Returns the resulting offset of the cursor from the beginning of the line.
.It Fn el_line
Return the editing information for the current line in a
.Fa LineInfo
structure, which is defined as follows:
.Bd -literal
typedef struct lineinfo {
    const char *buffer;    /* address of buffer */
    const char *cursor;    /* address of cursor */
    const char *lastchar;  /* address of last character */
} LineInfo;
.Ed
.Pp
.Fa buffer
is not NUL terminated.
This function may be called after
.Fn el_gets
to obtain the
.Fa LineInfo
structure pertaining to line returned by that function,
and from within user defined functions added with
.Dv EL_ADDFN .
.It Fn el_insertstr
Insert
.Fa str
into the line at the cursor.
Returns \-1 if
.Fa str
is empty or won't fit, and 0 otherwise.
.It Fn el_deletestr
Delete
.Fa count
characters before the cursor.
.El
.Sh HISTORY LIST FUNCTIONS
The history functions use a common data structure,
.Fa History ,
which is created by
.Fn history_init
and freed by
.Fn history_end .
.Pp
The following functions are available:
.Bl -tag -width 4n
.It Fn history_init
Initialize the history list, and return a data structure
to be used by all other history list functions, or
.Dv NULL
on failure.
.It Fn history_end
Clean up and finish with
.Fa h ,
assumed to have been created with
.Fn history_init .
.It Fn history
Perform operation
.Fa op
on the history list, with optional arguments as needed by the
operation.
.Fa ev
is changed accordingly to operation.
The following values for
.Fa op
are supported, along with the required argument list:
.Bl -tag -width 4n
.It Dv H_SETSIZE , Fa "int size"
Set size of history to
.Fa size
elements.
.It Dv H_GETSIZE
Get number of events currently in history.
.It Dv H_END
Cleans up and finishes with
.Fa h ,
assumed to be created with
.Fn history_init .
.It Dv H_CLEAR
Clear the history.
.It Dv H_FUNC , Fa "void *ptr" , Fa "history_gfun_t first" , \
Fa "history_gfun_t next" , Fa "history_gfun_t last" , \
Fa "history_gfun_t prev" , Fa "history_gfun_t curr" , \
Fa "history_sfun_t set" , Fa "history_vfun_t clear" , \
Fa "history_efun_t enter" , Fa "history_efun_t add"
Define functions to perform various history operations.
.Fa ptr
is the argument given to a function when it's invoked.
.It Dv H_FIRST
Return the first element in the history.
.It Dv H_LAST
Return the last element in the history.
.It Dv H_PREV
Return the previous element in the history.
It is newer than the current one.
.It Dv H_NEXT
Return the next element in the history.
It is older than the current one.
.It Dv H_CURR
Return the current element in the history.
.It Dv H_SET , Fa "int position"
Set the cursor to point to the requested element.
.It Dv H_ADD , Fa "const char *str"
Append
.Fa str
to the current element of the history, or perform the
.Dv H_ENTER
operation with argument
.Fa str
if there is no current element.
.It Dv H_APPEND , Fa "const char *str"
Append
.Fa str
to the last new element of the history.
.It Dv H_ENTER , Fa "const char *str"
Add
.Fa str
as a new element to the history and, if necessary,
removing the oldest entry to keep the list to the created size.
If
.Dv 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
.Fn history
returns 1; if it is ignored as a duplicate returns 0.
Finally
.Fn history
returns \-1 if an error occurred.
.It Dv H_PREV_STR , Fa "const char *str"
Return the closest previous event that starts with
.Fa str .
.It Dv H_NEXT_STR , Fa "const char *str"
Return the closest next event that starts with
.Fa str .
.It Dv H_PREV_EVENT , Fa "int e"
Return the previous event numbered
.Fa e .
.It Dv H_NEXT_EVENT , Fa "int e"
Return the next event numbered
.Fa e .
.It Dv H_LOAD , Fa "const char *file"
Load the history list stored in
.Fa file .
.It Dv H_SAVE , Fa "const char *file"
Save the history list to
.Fa file .
.It Dv H_SAVE_INCR , Fa "const char *file" , Fa "int e"
Append the history list since the event numbered
.Fa e
to
.Fa file .
.It Dv H_SAVE_FP , Fa "FILE *fp"
Save the history list to the opened
.Ft FILE
pointer
.Fa fp .
.It Dv H_SAVE_FP_INCR , Fa "FILE *fp" , Fa "int e"
Append the history list since the event numbered
.Fa e
to the opened
.Ft FILE
pointer
.Fa fp .
.It Dv H_SETUNIQUE , Fa "int unique"
Set flag that adjacent identical event strings should not be entered
into the history.
.It Dv H_GETUNIQUE
Retrieve the current setting if adjacent identical elements should
be entered into the history.
.It Dv H_DEL , Fa "int e"
Delete the event numbered
.Fa e .
This function is only provided for
.Xr readline 3
compatibility.
The caller is responsible for free'ing the string in the returned
.Fa HistEvent .
.El
.Pp
.Fn history
returns >= 0 if the operation
.Fa op
succeeds.
Otherwise, \-1 is returned and
.Fa ev
is updated to contain more details about the error.
.El
.Sh TOKENIZATION FUNCTIONS
The tokenization functions use a common data structure,
.Fa Tokenizer ,
which is created by
.Fn tok_init
and freed by
.Fn tok_end .
.Pp
The following functions are available:
.Bl -tag -width 4n
.It Fn tok_init
Initialize the tokenizer, and return a data structure
to be used by all other tokenizer functions.
.Fa IFS
contains the Input Field Separators, which defaults to
.Aq space ,
.Aq tab ,
and
.Aq newline
if
.Dv NULL .
.It Fn tok_end
Clean up and finish with
.Fa t ,
assumed to have been created with
.Fn tok_init .
.It Fn tok_reset
Reset the tokenizer state.
Use after a line has been successfully tokenized
by
.Fn tok_line
or
.Fn tok_str
and before a new line is to be tokenized.
.It Fn tok_line
Tokenize
.Fa li ,
If successful, modify:
.Fa argv
to contain the words,
.Fa argc
to contain the number of words,
.Fa cursorc
(if not
.Dv NULL )
to contain the index of the word containing the cursor,
and
.Fa cursoro
(if not
.Dv NULL )
to contain the offset within
.Fa argv[cursorc]
of the cursor.
.Pp
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
.Aq newline .
A positive exit code indicates that another line should be read
and tokenization attempted again.
.
.It Fn tok_str
A simpler form of
.Fn tok_line ;
.Fa str
is a NUL terminated string to tokenize.
.El
.
.\"XXX.Sh EXAMPLES
.\"XXX: provide some examples
.Sh SEE ALSO
.Xr sh 1 ,
.Xr signal 3 ,
.Xr termcap 3 ,
.Xr editrc 5 ,
.Xr termcap 5 ,
.Xr editline 7
.Sh HISTORY
The
.Nm
library first appeared in
.Bx 4.4 .
.Dv CC_REDISPLAY
appeared in
.Nx 1.3 .
.Dv CC_REFRESH_BEEP ,
.Dv EL_EDITMODE
and the readline emulation appeared in
.Nx 1.4 .
.Dv EL_RPROMPT
appeared in
.Nx 1.5 .
.Sh AUTHORS
.An -nosplit
The
.Nm
library was written by
.An Christos Zoulas .
.An Luke Mewburn
wrote this manual and implemented
.Dv CC_REDISPLAY ,
.Dv CC_REFRESH_BEEP ,
.Dv EL_EDITMODE ,
and
.Dv EL_RPROMPT .
.An Jaromir Dolecek
implemented the readline emulation.
.An Johny Mattsson
implemented wide-character support.
.Sh BUGS
At this time, it is the responsibility of the caller to
check the result of the
.Dv EL_EDITMODE
operation of
.Fn el_get
(after an
.Fn el_source
or
.Fn el_parse )
to determine if
.Nm
should be used for further input.
I.e.,
.Dv EL_EDITMODE
is purely an indication of the result of the most recent
.Xr editrc 5
.Ic edit
command.