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Diffstat (limited to 'shell/cmdedit.c')
-rw-r--r-- | shell/cmdedit.c | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/shell/cmdedit.c b/shell/cmdedit.c new file mode 100644 index 000000000..d1604f1d1 --- /dev/null +++ b/shell/cmdedit.c @@ -0,0 +1,405 @@ +/* + * 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 */ |