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1/* vi: set sw=4 ts=4: */
2/*
3 * Mini watch implementation for busybox
4 *
5 * Copyright (C) 2001 by Michael Habermann <mhabermann@gmx.de>
6 * Copyrigjt (C) Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
7 *
8 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
9 */
10
11/* BB_AUDIT SUSv3 N/A */
12/* BB_AUDIT GNU defects -- only option -n is supported. */
13
14#include "libbb.h"
15
16// procps 2.0.18:
17// watch [-d] [-n seconds]
18// [--differences[=cumulative]] [--interval=seconds] command
19//
20// procps-3.2.3:
21// watch [-dt] [-n seconds]
22// [--differences[=cumulative]] [--interval=seconds] [--no-title] command
23//
24// (procps 3.x and procps 2.x are forks, not newer/older versions of the same)
25
26int watch_main(int argc, char **argv);
27int watch_main(int argc, char **argv)
28{
29 unsigned opt;
30 unsigned period = 2;
31 unsigned cmdlen = 1; // 1 for terminal NUL
32 char *header = NULL;
33 char *cmd;
34 char *tmp;
35 char **p;
36
37 opt_complementary = "-1"; // at least one param please
38 opt = getopt32(argc, argv, "+dtn:", &tmp);
39 //if (opt & 0x1) // -d (ignore)
40 //if (opt & 0x2) // -t
41 if (opt & 0x4) period = xatou(tmp);
42 argv += optind;
43
44 p = argv;
45 while (*p)
46 cmdlen += strlen(*p++) + 1;
47 tmp = cmd = xmalloc(cmdlen);
48 while (*argv) {
49 tmp += sprintf(tmp, " %s", *argv);
50 argv++;
51 }
52 cmd++; // skip initial space
53
54 while (1) {
55 printf("\033[H\033[J");
56 if (!(opt & 0x2)) { // no -t
57 int width, len;
58 char *thyme;
59 time_t t;
60
61 get_terminal_width_height(STDOUT_FILENO, &width, 0);
62 header = xrealloc(header, width--);
63 // '%-*s' pads header with spaces to the full width
64 snprintf(header, width, "Every %ds: %-*s", period, width, cmd);
65 time(&t);
66 thyme = ctime(&t);
67 len = strlen(thyme);
68 if (len < width)
69 strcpy(header + width - len, thyme);
70 puts(header);
71 }
72 fflush(stdout);
73 // TODO: 'real' watch pipes cmd's output to itself
74 // and does not allow it to overflow the screen
75 // (taking into account linewrap!)
76 system(cmd);
77 sleep(period);
78 }
79 return 0; // gcc thinks we can reach this :)
80}