---
name: "el_source"
section: "3edit"
platform: "linux"
package: "libedit-dev"
version: "3.1-20140620-2"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/el_source/3edit"
---

# el\_source(3edit)

line editor, history and tokenization functions

## 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

library “libedit”

## 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 \*ch*);

*void*\

**el\_push**(*EditLine \*e*, *const char \*str*);

*void*\

**el\_wpush**(*EditLine \*e*, *const wchar\_t \*str*);

*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**();

*HistoryW* *\**\

**history\_winit**();

*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)](/sh/1.md).

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, *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**()

  Initialise the line editor, and return a data structure to be used by all other line editing functions. *prog* is the name of the invoking program, used when reading the [editrc(5)](/editrc/5.md) 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)](/stdio/3.md) corresponding streams, in case those were created with [funopen(3)](/funopen/3.md).

- **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\_getc**()

  Read a character from the tty. *ch* is modified to contain the character read. Returns the number of characters read if successful, -1 otherwise, in which case errno can be inspected for the cause.

- **el\_push**()

  Pushes *str* back onto the input stream. This is used by the macro expansion mechanism. Refer to the description of **bind** **-s** in [editrc(5)](/editrc/5.md) for more information.

- **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)](/editrc/5.md) for more information.

- **el\_set**()

  Set **editline** parameters. *op* determines which parameter to set, and each operation has its own parameter list.

  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* 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)](/editrc/5.md) for more information.

  - EL\_ECHOTC, *const char \**, *...*, NULL

    Perform the **echotc** builtin command. Refer to [editrc(5)](/editrc/5.md) for more information.

  - EL\_SETTC, *const char \**, *...*, NULL

    Perform the **settc** builtin command. Refer to [editrc(5)](/editrc/5.md) for more information.

  - EL\_SETTY, *const char \**, *...*, NULL

    Perform the **setty** builtin command. Refer to [editrc(5)](/editrc/5.md) for more information.

  - EL\_TELLTC, *const char \**, *...*, NULL

    Perform the **telltc** builtin command. Refer to [editrc(5)](/editrc/5.md) 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\_GETCFN, *int (\*f)(EditLine \*, char \*c)*

    Define the character reading function as *f*, which is to return the number of characters read and store them in *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, *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*

    Return a pointer to the function that displays the prompt in *f*. If *c* is not NULL, return the start/stop literal prompt character in it.

  - EL\_RPROMPT, *char \*(\*f)(EditLine \*)*, *char \*c*

    Return a pointer to the function that displays the prompt in *f*. If *c* is not NULL, return the start/stop literal prompt character in it.

  - EL\_EDITOR, *const char \*\**

    Return the name of the editor, which will be one of “emacs” or “vi”.

  - EL\_GETTC, *const char \*name*, *void \*value*

    Return non-zero if *name* is a valid [termcap(5)](/termcap/5.md) capability and set *value* to the current value of that capability.

  - EL\_SIGNAL, *int \**

    Return non-zero if **editline** has installed private signal handlers (see **el\_get**() above).

  - EL\_EDITMODE, *int \**

    Return non-zero if editing is enabled.

  - EL\_GETCFN, *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, *void \*\*data*

    Retrieve *data* previously registered with the corresponding **el\_set**() call.

  - EL\_UNBUFFERED, *int*

    Return non-zero if unbuffered mode is enabled.

  - EL\_PREP\_TERM, *int*

    Sets or clears terminal editing mode.

  - EL\_GETFP, *int fd*, *FILE \*\*fp*

    Return in *fp* the current **editline** file pointer for “input” *fd* = 0, “output” *fd* = 1, or “error” *fd* = 2.

- **el\_source**()

  Initialise **editline** by reading the contents of *file*. **el\_parse**() is called for each line in *file*. If *file* is NULL, try *$HOME/.editrc*. Refer to [editrc(5)](/editrc/5.md) for details on the format of *file*.

- **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**()

  Initialise the history list, and return a data structure to be used by all other history list functions.

- **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.

  - 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, *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 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, *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\_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)](/readline/3.md) 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**()

  Initialise 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)](/sh/1.md), [signal(3)](/signal/3.md), [termcap(3)](/termcap/3.md), [editrc(5)](/editrc/5.md), [termcap(5)](/termcap/5.md)

## 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)](/editrc/5.md) **edit** command.