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Diffstat (limited to '')
-rw-r--r-- | src/alarm.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/src/alarm.c b/src/alarm.c new file mode 100644 index 0000000..f66af7d --- /dev/null +++ b/src/alarm.c @@ -0,0 +1,95 @@ +/** + * alarm — Schedule an alarm for a program when starting it + * Copyright © 2014 Mattias Andrée (maandree@member.fsf.org) + * + * 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 3 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, see <http://www.gnu.org/licenses/>. + */ +#include <stdio.h> +#include <string.h> +#include <unistd.h> +#include <stdlib.h> +#include <stddef.h> + + +int main(int argc, char** argv) +{ + char** cmdline = NULL; + long hours = 0; + long minutes = 0; + long seconds = 0; + long buf = 0; + int hms = 0; + char* time; + + if (argc < 3) + goto usage; + + time = argv[1]; + while (*time) + { + char c = *time++; + if (('0' <= c) && (c <= '9')) + buf = buf * 10 - (c & 15); + else if (strchr("hms", c)) + { + if (c == 'h') hours = -buf; + else if (c == 'm') minutes = -buf; + else if (c == 's') seconds = -buf; + buf = 0, hms = 1; + } + else + goto usage; + } + if (!hms) + { + if (strlen(argv[1]) < 1) + return 0; + seconds = -buf; + } + + seconds += minutes * 60; + seconds += hours * 60 * 60; + if ((seconds < 1) || (65535 < seconds)) + goto usage; + + cmdline = malloc((size_t)(argc - 1) * sizeof(char*)); + if (cmdline == NULL) + goto fail; + memcpy(cmdline, argv + 2, (size_t)(argc - 2) * sizeof(char*)); + cmdline[argc - 2] = NULL; + + alarm((unsigned)seconds); + execvp(argv[2], cmdline); + + fail: + perror(*argv); + free(cmdline); + return 1; + + usage: + printf("USAGE: %s <TIME> <COMMAND> <ARGS...>\n", *argv); + printf("\n"); + printf("Recognised patterns for <TIME>:\n"); + printf("\n"); + printf(" <SECONDS>[s]\n"); + printf(" <MINUTES>m[<SECONDS>s]\n"); + printf(" <HOURS>h[<MINUTES>m][<SECONDS>s]\n"); + printf("\n"); + printf(" All values are non-negative integers, and"); + printf(" the interal must be greater than zero and\n"); + printf(" at most 18h12m15s.\n"); + printf("\n"); + return 1; +} + |