diff options
author | Glenn L McGrath <bug1@ihug.co.nz> | 2002-09-16 09:10:04 +0000 |
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committer | Glenn L McGrath <bug1@ihug.co.nz> | 2002-09-16 09:10:04 +0000 |
commit | 18b76e6f8047edf2e9e3d8fcc962a2e40ed8ffbd (patch) | |
tree | a43358d389b2e594341e993c7a86d44369244423 /coreutils/watch.c | |
parent | 8fede28c7408b2231a50c88da22c2e07f26f6d56 (diff) |
Watch applet by Michael Habermann
Diffstat (limited to 'coreutils/watch.c')
-rw-r--r-- | coreutils/watch.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/coreutils/watch.c b/coreutils/watch.c new file mode 100644 index 000000000..78ede4c1c --- /dev/null +++ b/coreutils/watch.c @@ -0,0 +1,104 @@ +/* vi: set sw=4 ts=4: */ +/* + * Mini watch implementation for busybox + * + * Copyright (C) 2001 by Michael Habermann <mhabermann@gmx.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +/* getopt not needed */ + +#include <stdio.h> +#include <errno.h> +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include "busybox.h" + +extern int watch_main(int argc, char **argv) +{ + const char date_argv[2][10] = { "date", "" }; + const char clrscr[] = + "\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"; + const int header_len = 40; + char header[header_len + 1]; + int period = 2; + char **cargv; + int cargc; + pid_t pid; + int old_stdout; + int i; + + if (argc < 2) { + show_usage(); + } else { + cargv = argv + 1; + cargc = argc - 1; + + /* don't use getopt, because it permutes the arguments */ + if (argc >= 3 && !strcmp(argv[1], "-n")) { + period = strtol(argv[2], NULL, 10); + if (period < 1) + show_usage(); + cargv += 2; + cargc -= 2; + } + } + + + /* create header */ + snprintf(header, header_len, "Every %ds: ", period); + for (i = 0; i < cargc && (strlen(header) + strlen(cargv[i]) < header_len); + i++) { + strcat(header, cargv[i]); + strcat(header, " "); + } + + /* fill with blanks */ + for (i = strlen(header); i < header_len; i++) + header[i] = ' '; + + header[header_len - 1] = '\0'; + + + /* thanks to lye, who showed me how to redirect stdin/stdout */ + old_stdout = dup(1); + + while (1) { + printf("%s%s", clrscr, header); + date_main(1, (char **) date_argv); + printf("\n"); + + pid = vfork(); /* vfork, because of ucLinux */ + if (pid > 0) { + //parent + wait(0); + sleep(period); + } else if (0 == pid) { + //child + close(1); + dup(old_stdout); + if (execvp(*cargv, cargv)) + error_msg_and_die("Couldn't run command\n"); + } else { + error_msg_and_die("Couldn't vfork\n"); + } + } + + + return EXIT_SUCCESS; +} |