diff options
Diffstat (limited to 'sys/ddb/db_input.c')
| -rw-r--r-- | sys/ddb/db_input.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/sys/ddb/db_input.c b/sys/ddb/db_input.c new file mode 100644 index 0000000..5ec7824 --- /dev/null +++ b/sys/ddb/db_input.c @@ -0,0 +1,268 @@ +/* + * Mach Operating System + * Copyright (c) 1991,1990 Carnegie Mellon University + * All Rights Reserved. + * + * Permission to use, copy, modify and distribute this software and its + * documentation is hereby granted, provided that both the copyright + * notice and this permission notice appear in all copies of the + * software, derivative works or modified versions, and any portions + * thereof, and that both notices appear in supporting documentation. + * + * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS + * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR + * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. + * + * Carnegie Mellon requests users of this software to return to + * + * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU + * School of Computer Science + * Carnegie Mellon University + * Pittsburgh PA 15213-3890 + * + * any improvements or extensions that they make and grant Carnegie the + * rights to redistribute these changes. + */ +/* + * HISTORY + * $Log: db_input.c,v $ + * Revision 1.1 1992/03/25 21:45:10 pace + * Initial revision + * + * Revision 2.4 91/02/14 14:41:53 mrt + * Add input line editing. + * [90/11/11 dbg] + * + * Revision 2.3 91/02/05 17:06:32 mrt + * Changed to new Mach copyright + * [91/01/31 16:18:13 mrt] + * + * Revision 2.2 90/08/27 21:51:03 dbg + * Reduce lint. + * [90/08/07 dbg] + * Created. + * [90/07/25 dbg] + * + */ +/* + * Author: David B. Golub, Carnegie Mellon University + * Date: 7/90 + */ + +#include "param.h" +#include "proc.h" +#include <ddb/db_output.h> + +/* + * Character input and editing. + */ + +/* + * We don't track output position while editing input, + * since input always ends with a new-line. We just + * reset the line position at the end. + */ +char * db_lbuf_start; /* start of input line buffer */ +char * db_lbuf_end; /* end of input line buffer */ +char * db_lc; /* current character */ +char * db_le; /* one past last character */ + +#define CTRL(c) ((c) & 0x1f) +#define isspace(c) ((c) == ' ' || (c) == '\t') +#define BLANK ' ' +#define BACKUP '\b' + +void +db_putstring(s, count) + char *s; + int count; +{ + while (--count >= 0) + cnputc(*s++); +} + +void +db_putnchars(c, count) + int c; + int count; +{ + while (--count >= 0) + cnputc(c); +} + +/* + * Delete N characters, forward or backward + */ +#define DEL_FWD 0 +#define DEL_BWD 1 +void +db_delete(n, bwd) + int n; + int bwd; +{ + register char *p; + + if (bwd) { + db_lc -= n; + db_putnchars(BACKUP, n); + } + for (p = db_lc; p < db_le-n; p++) { + *p = *(p+n); + cnputc(*p); + } + db_putnchars(BLANK, n); + db_putnchars(BACKUP, db_le - db_lc); + db_le -= n; +} + +/* returns TRUE at end-of-line */ +int +db_inputchar(c) + int c; +{ + switch (c) { + case CTRL('b'): + /* back up one character */ + if (db_lc > db_lbuf_start) { + cnputc(BACKUP); + db_lc--; + } + break; + case CTRL('f'): + /* forward one character */ + if (db_lc < db_le) { + cnputc(*db_lc); + db_lc++; + } + break; + case CTRL('a'): + /* beginning of line */ + while (db_lc > db_lbuf_start) { + cnputc(BACKUP); + db_lc--; + } + break; + case CTRL('e'): + /* end of line */ + while (db_lc < db_le) { + cnputc(*db_lc); + db_lc++; + } + break; + case CTRL('h'): + case 0177: + /* erase previous character */ + if (db_lc > db_lbuf_start) + db_delete(1, DEL_BWD); + break; + case CTRL('d'): + /* erase next character */ + if (db_lc < db_le) + db_delete(1, DEL_FWD); + break; + case CTRL('k'): + /* delete to end of line */ + if (db_lc < db_le) + db_delete(db_le - db_lc, DEL_FWD); + break; + case CTRL('t'): + /* twiddle last 2 characters */ + if (db_lc >= db_lbuf_start + 2) { + c = db_lc[-2]; + db_lc[-2] = db_lc[-1]; + db_lc[-1] = c; + cnputc(BACKUP); + cnputc(BACKUP); + cnputc(db_lc[-2]); + cnputc(db_lc[-1]); + } + break; + case CTRL('r'): + db_putstring("^R\n", 3); + if (db_le > db_lbuf_start) { + db_putstring(db_lbuf_start, db_le - db_lbuf_start); + db_putnchars(BACKUP, db_le - db_lc); + } + break; + case '\n': + case '\r': + *db_le++ = c; + return (1); + default: + if (db_le == db_lbuf_end) { + cnputc('\007'); + } + else if (c >= ' ' && c <= '~') { + register char *p; + + for (p = db_le; p > db_lc; p--) + *p = *(p-1); + *db_lc++ = c; + db_le++; + cnputc(c); + db_putstring(db_lc, db_le - db_lc); + db_putnchars(BACKUP, db_le - db_lc); + } + break; + } + return (0); +} + +int +db_readline(lstart, lsize) + char * lstart; + int lsize; +{ + db_force_whitespace(); /* synch output position */ + + db_lbuf_start = lstart; + db_lbuf_end = lstart + lsize; + db_lc = lstart; + db_le = lstart; + + while (!db_inputchar(cngetc())) + continue; + + db_putchar('\n'); /* synch output position */ + + *db_le = 0; + return (db_le - db_lbuf_start); +} + +void +db_check_interrupt() +{ + register int c; + + c = cnmaygetc(); + switch (c) { + case -1: /* no character */ + return; + + case CTRL('c'): + db_error((char *)0); + /*NOTREACHED*/ + + case CTRL('s'): + do { + c = cnmaygetc(); + if (c == CTRL('c')) + db_error((char *)0); + } while (c != CTRL('q')); + break; + + default: + /* drop on floor */ + break; + } +} + +cnmaygetc () +{ + return (-1); +} + +/* called from kdb_trap in db_interface.c */ +cnpollc (flag) +{ +} |
