Materiale rimasto indietro e prove con i timer POSIX

[gapil.git] / sources / mygetclock.c

diff --git a/sources/mygetclock.c b/sources/mygetclock.c
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+/* mygetclock.c
+ * 
+ * Copyright (C) 2010 Simone Piccardi
+ * 
+ * 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, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/*****************************************************************************
+ *
+ * File mygetclock.c: An example host command
+ *
+ * Author: S. Piccardi May. 2010
+ *
+ *****************************************************************************/
+#include <stdlib.h>      /* C standard library */
+#include <stdio.h>       /* standard I/O library */
+#include <unistd.h>      /* unix standard library */
+#include <time.h>        /* time library */
+
+
+/*
+ * Program mygetclock
+ */
+/* Help printing routine */
+void usage(void);
+
+int main(int argc, char *argv[]) 
+{
+/* 
+ * Variables definition
+ */
+    int i;
+    clockid_t clockid;
+    pid_t pid;
+    struct timespec time;
+    /*
+     * Input section: decode command line parameters 
+     * Use getopt function
+     */
+    opterr = 0;         /* don't want writing to stderr */
+    while ( (i = getopt(argc, argv, "h")) != -1) {
+       switch (i) {
+       /* 
+        * Handling options 
+        */ 
+       case 'h':                                            /* help option */
+           printf("Wrong -h option use\n");
+           usage();
+           return -1;
+           break;
+       case '?':                                    /* unrecognized options */
+           printf("Unrecognized options -%c\n",optopt);
+           usage();
+       default:                                       /* should not reached */
+           usage();
+       }
+    }
+    /* ***********************************************************
+     * 
+     *          Options processing completed
+     *
+     *               Main code beginning
+     * 
+     * ***********************************************************/
+    if ((argc - optind) != 1) {
+       printf("Wrong number of arguments %d\n", argc - optind);
+        usage();
+    }
+    
+    pid = atoi(argv[optind]);
+    if (pid > 0) {
+       if (clock_getcpuclockid(pid, &clockid) != 0) {
+           perror("Cannot get clockid");
+           exit(1);
+       }
+    } else {
+       clockid = CLOCK_PROCESS_CPUTIME_ID;
+    }
+    if (clock_gettime(clockid, &time) != 0) {
+       perror("Cannot get time");
+       exit(1);
+    } else {
+       printf("Tempo %s", ctime(&time.tv_sec));
+    }
+    exit(0);
+}
+/*
+ * routine to print usage info and exit
+ */
+void usage(void) {
+    printf("Program mygetclock: prende un orologio \n");
+    printf("Usage:\n");
+    printf("  mygetclock [-h] PID \n");
+    printf("  -h   print this help\n");
+    exit(1);
+}