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-rw-r--r--src/alarm.c95
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;
+}
+