Programma di prova per l'uso di {{{tee}}}

diff --git a/sources/tee.c b/sources/tee.c
new file mode 100644 (file)
index 0000000..4c4a872
--- /dev/null
+++ b/sources/tee.c
@@ -0,0 +1,85 @@
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <assert.h>
+#include <errno.h>
+#include <limits.h>
+
+
+int main(int argc, char *argv[])
+{
+   /*
+    * Variables definition
+    */
+    int i;
+    int size = 4096;
+    int fd;
+    int len, nwrite;
+    /*
+     * 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 's':      /* take wait time for childen */
+            size = strtol(optarg, NULL, 10);    /* convert input */
+            break;
+       case '?':      /* unrecognized options */
+            printf("Unrecognized options -%c\n", optopt);
+            usage();
+        default:       /* should not reached */
+            usage();
+        }
+    }
+   /*
+    * Main body
+    */
+    if ((argc - optind) != 1) { /* There must two argument */
+        printf("Wrong number of arguments %d\n", argc - optind);
+        usage();
+    }
+    /* open destination file */
+    fd = open(argv[1], O_WRONLY|O_CREAT|O_TRUNC, 0644);
+    if (fd == -1) {
+        printf("cannot open destination file %s, %s", argv[1], 
+              strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+    /* tee loop */
+    while (1) {
+        /* copy stdin to stdout */
+        len = tee(STDIN_FILENO, STDOUT_FILENO, size, SPLICE_F_NONBLOCK);
+        if (len < 0) {
+            if (errno == EAGAIN) {
+               continue;
+           } else {
+               perror("error on tee stdin to stdout");
+               exit(EXIT_FAILURE);
+           }
+        } else {
+            if (len == 0) break;
+       }
+        /* write data to the file using splice */
+        while (len > 0) {
+            nwrite = splice(STDIN_FILENO, NULL, fd, NULL, len, SPLICE_F_MOVE);
+            if (nwrite < 0) {
+                perror("error on splice stdin to file");
+                break;
+            }
+            len -= nwrite;
+        }
+    }
+    close(fd);
+    exit(EXIT_SUCCESS);
+}