editlineel_initel_endel_resetel_getsel_getcel_pushel_parseel_setel_getel_sourceel_resizeel_lineel_insertstrel_deletestrhistory_inithistory_endhistorytok_inittok_endtok_resettok_linetok_str
- line editor, history and tokenization functions
LIBRARY
Lb libedit
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); int
el_getc (EditLine *e char *ch); void
el_push (EditLine *e char *str); int
el_parse (EditLine *e int argc const char *argv[]); int
el_set (EditLine *e int op ...); int
el_get (EditLine *e int op ...); int
el_source (EditLine *e const char *file); void
el_resize (EditLine *e); const LineInfo *
el_line (EditLine *e); int
el_insertstr (EditLine *e const char *str); void
el_deletestr (EditLine *e int count); History *
history_init (); void
history_end (History *h); int
history (History *h HistEvent *ev int op ...); Tokenizer *
tok_init (const char *IFS); void
tok_end (Tokenizer *t); void
tok_reset (Tokenizer *t); int
Fo tok_line
Fa Tokenizer *t const LineInfo *li int *argc const char **argv[]
Fa int *cursorc int *cursoro
Fc Ft int
tok_str (Tokenizer *t const char *str int *argc const char **argv[]);
DESCRIPTION
The
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
LINE EDITING FUNCTIONS
The line editing functions use a common data structure,
Fa EditLine ,
which is created by
el_init ();
and freed by
el_end (.);
The following functions are available:
Fn el_init
Initialise the line editor, and return a data structure
to be used by all other line editing functions.
Fa prog
is the name of the invoking program, used when reading the
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
``the tty''
are actually to this input/output stream combination.
Fn el_end
Clean up and finish with
Fa e ,
assumed to have been created with
el_init (.);
Fn el_reset
Reset the tty and the parser.
This should be called after an error which may have upset the tty's
state.
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
NULL
if no characters were read or if an error occurred.
Fn el_getc
Read a character from the tty.
Fa ch
is modified to contain the character read.
Returns the number of characters read if successful, -1 otherwise.
Fn el_push
Pushes
Fa str
back onto the input stream.
This is used by the macro expansion mechanism.
Refer to the description of
bind
-s
in
editrc(5)
for more information.
Fn el_parse
Parses the
Fa argv
array (which is
Fa argc
elements in size)
to execute builtin
commands.
If the command is prefixed with
``prog:''
then
el_parse ();
will only execute the command if
``prog''
matches the
Fa prog
argument supplied to
el_init (.);
The return value is
-1 if the command is unknown,
0 if there was no error or
``prog''
did not match, or
1 if the command returned an error.
Refer to
editrc(5)
for more information.
Fn el_set
Set
parameters.
Fa op
determines which parameter to set, and each operation has its
own parameter list.
The following values for
Fa op
are supported, along with the required argument list:
EL_PROMPT , Fa char *(*f)(EditLine *)
Define prompt printing function as
Fa f ,
which is to return a string that contains the prompt.
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.
EL_TERMINAL , Fa const char *type
Define terminal type of the tty to be
Fa type ,
or to
TERM
if
Fa type
is
NULL
EL_EDITOR , Fa const char *mode
Set editing mode to
Fa mode ,
which must be one of
``emacs''
or
``vi''
EL_SIGNAL , Fa int flag
If
Fa flag
is non-zero,
will install its own signal handler for the following signals when
reading command input:
SIGCONTSIGHUPSIGINTSIGQUITSIGSTOPSIGTERMSIGTSTP
and
SIGWINCH
Otherwise, the current signal handlers will be used.
EL_BIND ,
Fa const char * ,
Fa ... ,
NULL
Perform the
bind
builtin command.
Refer to
editrc(5)
for more information.
EL_ECHOTC ,
Fa const char * ,
Fa ... ,
NULL
Perform the
echotc
builtin command.
Refer to
editrc(5)
for more information.
EL_SETTC ,
Fa const char * ,
Fa ... ,
NULL
Perform the
settc
builtin command.
Refer to
editrc(5)
for more information.
EL_SETTY ,
Fa const char * ,
Fa ... ,
NULL
Perform the
setty
builtin command.
Refer to
editrc(5)
for more information.
EL_TELLTC ,
Fa const char * ,
Fa ... ,
NULL
Perform the
telltc
builtin command.
Refer to
editrc(5)
for more information.
EL_ADDFN ,
Fa const char *name ,
Fa const char *help ,
Fa unsigned char (*func)(EditLine *e, int ch)
Add a user defined function,
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
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 ,
Fa History *(*func)(History *, int op, ...) ,
Fa const char *ptr
Defines which history function to use, which is usually
history (.);
Fa ptr
should be the value returned by
history_init (.);
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
.
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_GETCFN , Fa int (*f)(EditLine *, char *c)
Define the character reading function as
Fa f ,
which is to return the number of characters read and store them in
Fa c .
This function is called internally by
el_gets ();
and
el_getc (.);
The builtin function can be set or restored with the special function
name
EL_BUILTIN_GETCFN
EL_CLIENTDATA , Fa void *data
Register
Fa data
to be associated with this EditLine structure.
It can be retrieved with the corresponding
el_get ();
call.
EL_SETFP , Fa int fd , Fa FILE *fp
Set the current
editline
file pointer for
``input''
Fa fd
=
0
``output''
Fa fd
=
1
or
``error''
Fa fd
=
2
from
Fa fp .
Fn el_get
Get
parameters.
Fa op
determines which parameter to retrieve into
Fa result .
Returns 0 if successful, -1 otherwise.
The following values for
Fa op
are supported, along with actual type of
Fa result :
EL_PROMPT , Fa char *(*f)(EditLine *)
Return a pointer to the function that displays the prompt.
EL_RPROMPT , Fa char *(*f)(EditLine *)
Return a pointer to the function that displays the rightside prompt.
EL_EDITOR , Fa const char *
Return the name of the editor, which will be one of
``emacs''
or
``vi''
EL_GETTC , Fa const char *name , Fa void *value
Return non-zero if
Fa name
is a valid
termcap(5)
capability
and set
Fa value
to the current value of that capability.
EL_SIGNAL , Fa int *
Return non-zero if
has installed private signal handlers (see
el_get ();
above).
EL_EDITMODE , Fa int *
Return non-zero if editing is enabled.
EL_GETCFN , Fa int (**f)(EditLine *, char *)
Return a pointer to the function that read characters, which is equal to
EL_BUILTIN_GETCFN
in the case of the default builtin function.
EL_CLIENTDATA , Fa void **data
Retrieve
Fa data
previously registered with the corresponding
el_set ();
call.
EL_UNBUFFERED , Fa int
Sets or clears unbuffered mode.
In this mode,
el_gets ();
will return immediately after processing a single character.
EL_PREP_TERM , Fa int
Sets or clears terminal editing mode.
EL_GETFP , Fa int fd, Fa FILE **fp
Return in
Fa fp
the current
editline
file pointer for
``input''
Fa fd
=
0
``output''
Fa fd
=
1
or
``error''
Fa fd
=
2
Fn el_source
Initialise
by reading the contents of
Fa file .
el_parse ();
is called for each line in
Fa file .
If
Fa file
is
NULL
try
$PWD/.editrc
then
$HOME/.editrc
Refer to
editrc(5)
for details on the format of
Fa file .
Fn 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 is the responsibility of the application to call
el_resize ();
on the appropriate occasions.
Fn el_line
Return the editing information for the current line in a
Fa 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;
Fa buffer
is not NUL terminated.
This function may be called after
el_gets ();
to obtain the
Fa LineInfo
structure pertaining to line returned by that function,
and from within user defined functions added with
EL_ADDFN
Fn el_insertstr
Insert
Fa str
into the line at the cursor.
Returns -1 if
Fa str
is empty or will not fit, and 0 otherwise.
Fn el_deletestr
Delete
Fa count
characters before the cursor.
HISTORY LIST FUNCTIONS
The history functions use a common data structure,
Fa History ,
which is created by
history_init ();
and freed by
history_end (.);
The following functions are available:
Fn history_init
Initialise the history list, and return a data structure
to be used by all other history list functions.
Fn history_end
Clean up and finish with
Fa h ,
assumed to have been created with
history_init (.);
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:
H_SETSIZE , Fa int size
Set size of history to
Fa size
elements.
H_GETSIZE
Get number of events currently in history.
H_END
Cleans up and finishes with
Fa h ,
assumed to be created with
history_init (.);
H_CLEAR
Clear the history.
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 is 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.
H_NEXT
Return the next element in the history.
H_CURR
Return the current element in the history.
H_SET
Set the cursor to point to the requested element.
H_ADD , Fa const char *str
Append
Fa str
to the current element of the history, or perform the
H_ENTER
operation with argument
Fa str
if there is no current element.
H_APPEND , Fa const char *str
Append
Fa str
to the last new element of the history.
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
H_SETUNIQUE
was has been called with a non-zero arguments, 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 , Fa const char *str
Return the closest previous event that starts with
Fa str .
H_NEXT_STR , Fa const char *str
Return the closest next event that starts with
Fa str .
H_PREV_EVENT , Fa int e
Return the previous event numbered
Fa e .
H_NEXT_EVENT , Fa int e
Return the next event numbered
Fa e .
H_LOAD , Fa const char *file
Load the history list stored in
Fa file .
H_SAVE , Fa const char *file
Save the history list to
Fa file .
H_SETUNIQUE , Fa 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 , Fa int e
Delete the event numbered
Fa e .
This function is only provided for
readline(3)
compatibility.
The caller is responsible for free'ing the string in the returned
Fa HistEvent .
The
history ();
function returns Ge] 0 if the operation
Fa op
succeeds.
Otherwise, -1 is returned and
Fa ev
is updated to contain more details about the error.
TOKENIZATION FUNCTIONS
The tokenization functions use a common data structure,
Fa Tokenizer ,
which is created by
tok_init ();
and freed by
tok_end (.);
The following functions are available:
Fn tok_init
Initialise 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
NULL
Fn tok_end
Clean up and finish with
Fa t ,
assumed to have been created with
tok_init (.);
Fn 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.
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
NULL
to contain the index of the word containing the cursor,
and
Fa cursoro
(if not
NULL
to contain the offset within
Fa 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
Aq newline .
A positive exit code indicates that another line should be read
and tokenization attempted again.
Fn tok_str
A simpler form of
tok_line (;);
Fa str
is a NUL terminated string to tokenize.
The
library first appeared in
BSD 4.4
CC_REDISPLAY
appeared in
Nx 1.3 .
CC_REFRESH_BEEP
and
EL_EDITMODE
appeared in
Nx 1.4 .
EL_RPROMPT
appeared in
Nx 1.5 .
AUTHORS
An -nosplit
The
library was written by
An Christos Zoulas .
An Luke Mewburn
wrote this manual and implemented
CC_REDISPLAYCC_REFRESH_BEEPEL_EDITMODE
and
EL_RPROMPT
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
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.