emailler/apps/linenoise.c
2018-10-30 20:00:17 +01:00

556 lines
16 KiB
C

/* linenoise.c -- guerrilla line editing library against the idea that a
* line editing lib needs to be 20,000 lines of C code.
*
* You can find the latest source code at:
*
* http://github.com/antirez/linenoise
*
* Does a number of crazy assumptions that happen to be true in 99.9999% of
* the 2010 UNIX computers around.
*
* ------------------------------------------------------------------------
*
* Copyright (c) 2010-2016, Salvatore Sanfilippo <antirez at gmail dot com>
* Copyright (c) 2010-2013, Pieter Noordhuis <pcnoordhuis at gmail dot com>
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* ------------------------------------------------------------------------
*/
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <conio.h>
#ifdef __APPLE2__
#include <apple2_filetype.h>
#endif
#include "linenoise.h"
#define LINENOISE_HISTORY_MAX_LEN 20
#define LINENOISE_MAX_LINE 256
static char buf[LINENOISE_MAX_LINE];
static linenoiseCompletionCallback *completionCallback = NULL;
static int history_len = 0;
static char **history = NULL;
/* The linenoiseState structure represents the state during line editing.
* We pass this state to functions implementing specific editing
* functionalities. */
struct linenoiseState {
char *buf; /* Edited line buffer. */
size_t buflen; /* Edited line buffer size. */
const char *prompt; /* Prompt to display. */
size_t plen; /* Prompt length. */
size_t pos; /* Current cursor position. */
size_t oldpos; /* Previous refresh cursor position. */
size_t len; /* Current edited line length. */
size_t cols; /* Number of columns in terminal. */
int history_index; /* The history index we are currently editing. */
};
enum KEY_ACTION{
CTRL_A = 1, /* Ctrl+a */
CTRL_B = 2, /* Ctrl-b */
CTRL_C = 3, /* Ctrl-c */
CTRL_D = 4, /* Ctrl-d */
CTRL_E = 5, /* Ctrl-e */
CTRL_F = 6, /* Ctrl-f */
CTRL_N = 14, /* Ctrl-n */
CTRL_P = 16 /* Ctrl-p */
};
static void refreshLine(struct linenoiseState *l);
/* ======================= Low level terminal handling ====================== */
/* Try to get the number of columns in the current terminal, or assume 80
* if it fails. */
static int getColumns() {
unsigned char cols, rows;
screensize(&cols,&rows);
return cols;
}
#ifdef __APPLE2__
#pragma code-name (push, "LC")
#endif
/* Beep, used for completion when there is nothing to complete or when all
* the choices were already shown. */
static void linenoiseBeep(void) {
putchar('\a');
}
/* ============================== Completion ================================ */
/* Free a list of completion option populated by linenoiseAddCompletion(). */
static void freeCompletions(linenoiseCompletions *lc) {
size_t i;
for (i = 0; i < lc->len; i++)
free(lc->cvec[i]);
if (lc->cvec != NULL)
free(lc->cvec);
}
/* This is an helper function for linenoiseEdit() and is called when the
* user types the <tab> key in order to complete the string currently in the
* input.
*
* The state of the editing is encapsulated into the pointed linenoiseState
* structure as described in the structure definition. */
static int completeLine(register struct linenoiseState *ls) {
linenoiseCompletions lc = { 0, NULL };
int nwritten;
char c = 0;
completionCallback(ls->buf,&lc);
if (lc.len == 0) {
linenoiseBeep();
} else {
size_t stop = 0, i = 0;
while(!stop) {
/* Show completion or original buffer */
if (i < lc.len) {
struct linenoiseState saved;
saved = *ls;
ls->len = ls->pos = strlen(lc.cvec[i]);
ls->buf = lc.cvec[i];
refreshLine(ls);
ls->len = saved.len;
ls->pos = saved.pos;
ls->buf = saved.buf;
} else {
refreshLine(ls);
}
c = cgetc();
switch(c) {
case '\t': /* tab */
i = (i+1) % (lc.len+1);
if (i == lc.len) linenoiseBeep();
break;
case CH_ESC: /* escape */
/* Re-show original buffer */
if (i < lc.len) refreshLine(ls);
stop = 1;
break;
default:
/* Update buffer and return */
if (i < lc.len) {
nwritten = snprintf(ls->buf,ls->buflen,"%s",lc.cvec[i]);
ls->len = ls->pos = nwritten;
}
stop = 1;
break;
}
}
}
freeCompletions(&lc);
return c; /* Return last read character */
}
/* Register a callback function to be called for tab-completion. */
void linenoiseSetCompletionCallback(linenoiseCompletionCallback *fn) {
completionCallback = fn;
}
/* This function is used by the callback function registered by the user
* in order to add completion options given the input string when the
* user typed <tab>. See the example.c source code for a very easy to
* understand example. */
void linenoiseAddCompletion(linenoiseCompletions *lc, const char *str) {
size_t len = strlen(str);
char *copy, **cvec;
copy = malloc(len+1);
if (copy == NULL) return;
memcpy(copy,str,len+1);
cvec = realloc(lc->cvec,sizeof(char*)*(lc->len+1));
if (cvec == NULL) {
free(copy);
return;
}
lc->cvec = cvec;
lc->cvec[lc->len++] = copy;
}
/* =========================== Line editing ================================= */
/* Low level line refresh.
*
* Rewrite the currently edited line accordingly to the buffer content,
* cursor position, and number of columns of the terminal. */
static void refreshLine(struct linenoiseState *l) {
char tmp;
unsigned char y = wherey();
size_t plen = strlen(l->prompt);
char *buf = l->buf;
size_t len = l->len;
size_t pos = l->pos;
while((plen+pos) >= l->cols) {
buf++;
len--;
pos--;
}
while (plen+len > l->cols) {
len--;
}
/* Cursor to left edge */
gotox(0);
/* Write the prompt */
cputs(l->prompt);
/* Write the current buffer content */
tmp = buf[len];
buf[len] = '\0';
cputs(buf);
buf[len] = tmp;
/* Erase to right */
if (wherex()) {
cclear(l->cols-wherex());
}
/* Move cursor to original position. */
gotoxy((unsigned char)(pos+plen),y);
}
/* Insert the character 'c' at cursor current position. */
void linenoiseEditInsert(register struct linenoiseState *l, char c) {
if (l->len < l->buflen) {
if (l->len == l->pos) {
l->buf[l->pos] = c;
l->pos++;
l->len++;
l->buf[l->len] = '\0';
if ((l->plen+l->len < l->cols)) {
/* Avoid a full update of the line in the
* trivial case. */
cputc(c);
} else {
refreshLine(l);
}
} else {
memmove(l->buf+l->pos+1,l->buf+l->pos,l->len-l->pos);
l->buf[l->pos] = c;
l->len++;
l->pos++;
l->buf[l->len] = '\0';
refreshLine(l);
}
}
}
/* Move cursor on the left. */
void linenoiseEditMoveLeft(struct linenoiseState *l) {
if (l->pos > 0) {
l->pos--;
refreshLine(l);
}
}
/* Move cursor on the right. */
void linenoiseEditMoveRight(struct linenoiseState *l) {
if (l->pos != l->len) {
l->pos++;
refreshLine(l);
}
}
/* Move cursor to the start of the line. */
void linenoiseEditMoveHome(struct linenoiseState *l) {
if (l->pos != 0) {
l->pos = 0;
refreshLine(l);
}
}
/* Move cursor to the end of the line. */
void linenoiseEditMoveEnd(struct linenoiseState *l) {
if (l->pos != l->len) {
l->pos = l->len;
refreshLine(l);
}
}
/* Substitute the currently edited line with the next or previous history
* entry as specified by 'dir'. */
#define LINENOISE_HISTORY_NEXT 0
#define LINENOISE_HISTORY_PREV 1
void linenoiseEditHistoryNext(register struct linenoiseState *l, int dir) {
if (history_len > 1) {
/* Update the current history entry before to
* overwrite it with the next one. */
free(history[history_len - 1 - l->history_index]);
history[history_len - 1 - l->history_index] = strdup(l->buf);
/* Show the new entry */
l->history_index += (dir == LINENOISE_HISTORY_PREV) ? 1 : -1;
if (l->history_index < 0) {
l->history_index = 0;
return;
} else if (l->history_index >= history_len) {
l->history_index = history_len-1;
return;
}
strncpy(l->buf,history[history_len - 1 - l->history_index],l->buflen);
l->buf[l->buflen-1] = '\0';
l->len = l->pos = strlen(l->buf);
refreshLine(l);
}
}
/* Delete the character at the right of the cursor without altering the cursor
* position. Basically this is what happens with the "Delete" keyboard key. */
void linenoiseEditDelete(register struct linenoiseState *l) {
if (l->len > 0 && l->pos < l->len) {
memmove(l->buf+l->pos,l->buf+l->pos+1,l->len-l->pos-1);
l->len--;
l->buf[l->len] = '\0';
refreshLine(l);
}
}
/* Backspace implementation. */
void linenoiseEditBackspace(register struct linenoiseState *l) {
if (l->pos > 0 && l->len > 0) {
memmove(l->buf+l->pos-1,l->buf+l->pos,l->len-l->pos);
l->pos--;
l->len--;
l->buf[l->len] = '\0';
refreshLine(l);
}
}
/* This function is the core of the line editing capability of linenoise.
*
* The resulting string is put into 'buf' when the user type enter.
*
* The function returns the length of the current buffer. */
static int linenoiseEdit(const char *prompt)
{
struct linenoiseState l;
/* Populate the linenoise state that we pass to functions implementing
* specific editing functionalities. */
l.buf = buf;
l.buflen = LINENOISE_MAX_LINE;
l.prompt = prompt;
l.plen = strlen(prompt);
l.oldpos = l.pos = 0;
l.len = 0;
l.cols = getColumns();
l.history_index = 0;
/* Buffer starts empty. */
l.buf[0] = '\0';
l.buflen--; /* Make sure there is always space for the nulterm */
/* The latest history entry is always our current buffer, that
* initially is just an empty string. */
linenoiseHistoryAdd("");
cputs(prompt);
while(1) {
char c;
c = cgetc();
/* Only autocomplete when the callback is set. It will return the
* character that should be handled next. */
if (c == '\t' && completionCallback != NULL) {
c = completeLine(&l);
/* Read next character when 0 */
if (c == 0) continue;
}
switch(c) {
case CH_ENTER:
history_len--;
free(history[history_len]);
return (int)l.len;
case CTRL_C:
errno = EAGAIN;
return -1;
case CH_DEL: /* backspace */
linenoiseEditBackspace(&l);
break;
case CTRL_D: /* ctrl-d, remove char at right of cursor. */
if (l.len > 0) {
linenoiseEditDelete(&l);
}
break;
case CTRL_B: /* ctrl-b */
case CH_CURS_LEFT:
linenoiseEditMoveLeft(&l);
break;
case CTRL_F: /* ctrl-f */
case CH_CURS_RIGHT:
linenoiseEditMoveRight(&l);
break;
case CTRL_P: /* ctrl-p */
case CH_CURS_UP:
linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_PREV);
break;
case CTRL_N: /* ctrl-n */
case CH_CURS_DOWN:
linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_NEXT);
break;
case CTRL_A: /* Ctrl+a, go to the start of the line */
linenoiseEditMoveHome(&l);
break;
case CTRL_E: /* ctrl+e, go to the end of the line */
linenoiseEditMoveEnd(&l);
break;
default:
if (isprint(c)) linenoiseEditInsert(&l,c);
break;
}
}
return l.len;
}
#ifdef __APPLE2__
#pragma code-name (pop)
#endif
/* The high level function that is the main API of the linenoise library. */
char *linenoise(const char *prompt) {
unsigned char oldcursor;
int count;
oldcursor = cursor(1);
count = linenoiseEdit(prompt);
cursor(oldcursor);
if (count == -1) return NULL;
return buf;
}
/* ================================ History ================================= */
/* Reseet the history. */
void linenoiseHistoryReset(void) {
if (history) {
int j;
for (j = 0; j < history_len; j++)
free(history[j]);
free(history);
history_len = 0;
history = NULL;
}
}
/* This is the API call to add a new entry in the linenoise history.
* It uses a fixed array of char pointers that are shifted (memmoved)
* when the history max length is reached in order to remove the older
* entry and make room for the new one, so it is not exactly suitable for huge
* histories, but will work well for a few hundred of entries.
*
* Using a circular buffer is smarter, but a bit more complex to handle. */
int linenoiseHistoryAdd(const char *line) {
char *linecopy;
/* Initialization on first call. */
if (history == NULL) {
history = malloc(sizeof(char*)*LINENOISE_HISTORY_MAX_LEN);
if (history == NULL) return 0;
memset(history,0,(sizeof(char*)*LINENOISE_HISTORY_MAX_LEN));
}
/* Don't add duplicated lines. */
if (history_len && !strcmp(history[history_len-1], line)) return 0;
/* Add an heap allocated copy of the line in the history.
* If we reached the max length, remove the older line. */
linecopy = strdup(line);
if (!linecopy) return 0;
if (history_len == LINENOISE_HISTORY_MAX_LEN) {
free(history[0]);
memmove(history,history+1,sizeof(char*)*(LINENOISE_HISTORY_MAX_LEN-1));
history_len--;
}
history[history_len] = linecopy;
history_len++;
return 1;
}
/* Save the history in the specified file. On success 0 is returned
* otherwise -1 is returned. */
int linenoiseHistorySave(const char *filename) {
FILE *fp;
int j;
#ifdef __APPLE2__
unsigned char oldfiletype = _filetype;
_filetype = PRODOS_T_TXT;
#endif
fp = fopen(filename,"w");
#ifdef __APPLE2__
_filetype = oldfiletype;
#endif
if (fp == NULL) return -1;
for (j = 0; j < history_len; j++)
fprintf(fp,"%s\n",history[j]);
fclose(fp);
return 0;
}
/* Load the history from the specified file. If the file does not exist
* zero is returned and no operation is performed.
*
* If the file exists and the operation succeeded 0 is returned, otherwise
* on error -1 is returned. */
int linenoiseHistoryLoad(const char *filename) {
FILE *fp = fopen(filename,"r");
if (fp == NULL) return -1;
while (fgets(buf,LINENOISE_MAX_LINE,fp) != NULL) {
char *p;
p = strchr(buf,'\r');
if (!p) p = strchr(buf,'\n');
if (p) *p = '\0';
linenoiseHistoryAdd(buf);
}
fclose(fp);
return 0;
}