/*
* Termios command line History and Editting for NetBSD sh (ash)
* Copyright (c) 1999
* Main code: Adam Rogoyski <rogoyski@cs.utexas.edu>
* Etc: Dave Cinege <dcinege@psychosis.com>
* Adjusted for busybox: Erik Andersen <andersee@debian.org>
*
* You may use this code as you wish, so long as the original author(s)
* are attributed in any redistributions of the source code.
* This code is 'as is' with no warranty.
* This code may safely be consumed by a BSD or GPL license.
*
* v 0.5 19990328 Initial release
*
* Future plans: Simple file and path name completion. (like BASH)
*
*/
/*
Usage and Known bugs:
Terminal key codes are not extensive, and more will probably
need to be added. This version was created on Debian GNU/Linux 2.x.
Delete, Backspace, Home, End, and the arrow keys were tested
to work in an Xterm and console. Ctrl-A also works as Home.
Ctrl-E also works as End. The binary size increase is <3K.
Editting will not display correctly for lines greater then the
terminal width. (more then one line.) However, history will.
*/
#include "internal.h"
#ifdef BB_FEATURE_SH_COMMAND_EDITING
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <termio.h>
#include <ctype.h>
#include <signal.h>
#include "cmdedit.h"
#define MAX_HISTORY 15 /* Maximum length of the linked list for the command line history */
#define ESC 27
#define DEL 127
static struct history *his_front = NULL; /* First element in command line list */
static struct history *his_end = NULL; /* Last element in command line list */
static struct termio old_term, new_term; /* Current termio and the previous termio before starting ash */
static int history_counter = 0; /* Number of commands in history list */
static int reset_term = 0; /* Set to true if the terminal needs to be reset upon exit */
char *parsenextc; /* copy of parsefile->nextc */
struct history {
char *s;
struct history *p;
struct history *n;
};
/* Version of write which resumes after a signal is caught. */
int xwrite(int fd, char *buf, int nbytes)
{
int ntry;
int i;
int n;
n = nbytes;
ntry = 0;
for (;;) {
i = write(fd, buf, n);
if (i > 0) {
if ((n -= i) <= 0)
return nbytes;
buf += i;
ntry = 0;
} else if (i == 0) {
if (++ntry > 10)
return nbytes - n;
} else if (errno != EINTR) {
return -1;
}
}
}
/* Version of ioctl that retries after a signal is caught. */
int xioctl(int fd, unsigned long request, char *arg)
{
int i;
while ((i = ioctl(fd, request, arg)) == -1 && errno == EINTR);
return i;
}
void cmdedit_reset_term(void)
{
if (reset_term)
xioctl(fileno(stdin), TCSETA, (void *) &old_term);
}
void gotaSignal(int sig)
{
cmdedit_reset_term();
fprintf(stdout, "\n");
exit(TRUE);
}
void input_home(int outputFd, int *cursor)
{ /* Command line input routines */
while (*cursor > 0) {
xwrite(outputFd, "\b", 1);
--*cursor;
}
}
void input_delete(int outputFd, int cursor)
{
int j = 0;
memmove(parsenextc + cursor, parsenextc + cursor + 1,
BUFSIZ - cursor - 1);
for (j = cursor; j < (BUFSIZ - 1); j++) {
if (!*(parsenextc + j))
break;
else
xwrite(outputFd, (parsenextc + j), 1);
}
xwrite(outputFd, " \b", 2);
while (j-- > cursor)
xwrite(outputFd, "\b", 1);
}
void input_end(int outputFd, int *cursor, int len)
{
while (*cursor < len) {
xwrite(outputFd, "\033[C", 3);
++*cursor;
}
}
void input_backspace(int outputFd, int *cursor, int *len)
{
int j = 0;
if (*cursor > 0) {
xwrite(outputFd, "\b \b", 3);
--*cursor;
memmove(parsenextc + *cursor, parsenextc + *cursor + 1,
BUFSIZ - *cursor + 1);
for (j = *cursor; j < (BUFSIZ - 1); j++) {
if (!*(parsenextc + j))
break;
else
xwrite(outputFd, (parsenextc + j), 1);
}
xwrite(outputFd, " \b", 2);
while (j-- > *cursor)
xwrite(outputFd, "\b", 1);
--*len;
}
}
extern int cmdedit_read_input(int inputFd, int outputFd,
char command[BUFSIZ])
{
int nr = 0;
int len = 0;
int j = 0;
int cursor = 0;
int break_out = 0;
int ret = 0;
char c = 0;
struct history *hp = his_end;
memset(command, 0, sizeof(command));
parsenextc = command;
if (!reset_term) {
xioctl(inputFd, TCGETA, (void *) &old_term);
memcpy(&new_term, &old_term, sizeof(struct termio));
new_term.c_cc[VMIN] = 1;
new_term.c_cc[VTIME] = 0;
new_term.c_lflag &= ~ICANON; /* unbuffered input */
new_term.c_lflag &= ~ECHO;
xioctl(inputFd, TCSETA, (void *) &new_term);
reset_term = 1;
} else {
xioctl(inputFd, TCSETA, (void *) &new_term);
}
memset(parsenextc, 0, BUFSIZ);
while (1) {
if ((ret = read(inputFd, &c, 1)) < 1)
return ret;
switch (c) {
case 1: /* Control-A Beginning of line */
input_home(outputFd, &cursor);
break;
case 5: /* Control-E EOL */
input_end(outputFd, &cursor, len);
break;
case 4: /* Control-D */
if (cursor != len) {
input_delete(outputFd, cursor);
len--;
}
break;
case '\b': /* Backspace */
case DEL:
input_backspace(outputFd, &cursor, &len);
break;
case '\n': /* Enter */
*(parsenextc + len++ + 1) = c;
xwrite(outputFd, &c, 1);
break_out = 1;
break;
case ESC: /* escape sequence follows */
if ((ret = read(inputFd, &c, 1)) < 1)
return ret;
if (c == '[') { /* 91 */
if ((ret = read(inputFd, &c, 1)) < 1)
return ret;
switch (c) {
case 'A':
if (hp && hp->p) { /* Up */
hp = hp->p;
goto hop;
}
break;
case 'B':
if (hp && hp->n && hp->n->s) { /* Down */
hp = hp->n;
goto hop;
}
break;
hop: /* hop */
len = strlen(parsenextc);
for (; cursor > 0; cursor--) /* return to begining of line */
xwrite(outputFd, "\b", 1);
for (j = 0; j < len; j++) /* erase old command */
xwrite(outputFd, " ", 1);
for (j = len; j > 0; j--) /* return to begining of line */
xwrite(outputFd, "\b", 1);
strcpy(parsenextc, hp->s); /* write new command */
len = strlen(hp->s);
xwrite(outputFd, parsenextc, len);
cursor = len;
break;
case 'C': /* Right */
if (cursor < len) {
xwrite(outputFd, "\033[C", 3);
cursor++;
}
break;
case 'D': /* Left */
if (cursor > 0) {
xwrite(outputFd, "\033[D", 3);
cursor--;
}
break;
case '3': /* Delete */
if (cursor != len) {
input_delete(outputFd, cursor);
len--;
}
break;
case '1': /* Home (Ctrl-A) */
input_home(outputFd, &cursor);
break;
case '4': /* End (Ctrl-E) */
input_end(outputFd, &cursor, len);
break;
}
if (c == '1' || c == '3' || c == '4')
if ((ret = read(inputFd, &c, 1)) < 1)
return ret; /* read 126 (~) */
}
if (c == 'O') { /* 79 */
if ((ret = read(inputFd, &c, 1)) < 1)
return ret;
switch (c) {
case 'H': /* Home (xterm) */
input_home(outputFd, &cursor);
break;
case 'F': /* End (xterm) */
input_end(outputFd, &cursor, len);
break;
}
}
c = 0;
break;
default: /* If it's regular input, do the normal thing */
if (!isprint(c)) /* Skip non-printable characters */
break;
if (len >= (BUFSIZ - 2)) /* Need to leave space for enter */
break;
len++;
if (cursor == (len - 1)) { /* Append if at the end of the line */
*(parsenextc + cursor) = c;
} else { /* Insert otherwise */
memmove(parsenextc + cursor + 1, parsenextc + cursor,
len - cursor - 1);
*(parsenextc + cursor) = c;
for (j = cursor; j < len; j++)
xwrite(outputFd, parsenextc + j, 1);
for (; j > cursor; j--)
xwrite(outputFd, "\033[D", 3);
}
cursor++;
xwrite(outputFd, &c, 1);
break;
}
if (break_out) /* Enter is the command terminator, no more input. */
break;
}
nr = len + 1;
xioctl(inputFd, TCSETA, (void *) &old_term);
reset_term = 0;
if (*(parsenextc)) { /* Handle command history log */
struct history *h = his_end;
if (!h) { /* No previous history */
h = his_front = malloc(sizeof(struct history));
h->n = malloc(sizeof(struct history));
h->p = NULL;
h->s = strdup(parsenextc);
h->n->p = h;
h->n->n = NULL;
h->n->s = NULL;
his_end = h->n;
history_counter++;
} else { /* Add a new history command */
h->n = malloc(sizeof(struct history));
h->n->p = h;
h->n->n = NULL;
h->n->s = NULL;
h->s = strdup(parsenextc);
his_end = h->n;
if (history_counter >= MAX_HISTORY) { /* After max history, remove the last known command */
struct history *p = his_front->n;
p->p = NULL;
free(his_front->s);
free(his_front);
his_front = p;
} else {
history_counter++;
}
}
}
return nr;
}
extern void cmdedit_init(void)
{
atexit(cmdedit_reset_term);
signal(SIGINT, gotaSignal);
signal(SIGQUIT, gotaSignal);
signal(SIGTERM, gotaSignal);
}
#endif /* BB_FEATURE_SH_COMMAND_EDITING */