Esempio di copia con {{{splice}}} e fine della trattazione della stessa.

[gapil.git] / listati / splicecp.c

diff --git a/listati/splicecp.c b/listati/splicecp.c
new file mode 100644 (file)
index 0000000..28a6705
--- /dev/null
+++ b/listati/splicecp.c
@@ -0,0 +1,61 @@
+#define _GNU_SOURCE
+#include <fcntl.h>       /* file control functions */
+...
+
+int main(int argc, char *argv[])
+{
+    int size = 4096;
+    int pipefd[2];
+    int in_fd, out_fd;
+    int nread, nwrite;
+    ...
+   /* Main body */
+    if ((argc - optind) != 2) { /* There must two argument */
+        printf("Wrong number of arguments %d\n", argc - optind);
+        usage();
+    }
+    /* open pipe, input and output file */
+    in_fd = open(argv[optind], O_RDONLY);
+    if (in_fd < 0) {
+       printf("Input error %s on %s\n", strerror(errno), argv[optind]);
+       exit(EXIT_FAILURE); 
+    }
+    out_fd = open(argv[optind+1], O_CREAT|O_RDWR|O_TRUNC, 0644);
+    if (out_fd < 0) {
+       printf("Cannot open %s, error %s\n", argv[optind+1], strerror(errno));
+       exit(EXIT_FAILURE); 
+    }
+    if (pipe(pipefd) == -1) {
+       perror("Cannot create buffer pipe"); 
+       exit(EXIT_FAILURE); 
+    }
+    /* copy loop */
+    while (1) {
+       nread = splice(in_fd, NULL, pipefd[1], NULL, size, 
+                      SPLICE_F_MOVE|SPLICE_F_MORE);
+       if (nread == 0) break;
+       if (nread < 0) {
+           if (errno == EINTR) {
+               continue;
+           } else {
+               perror("read error");
+               exit(EXIT_FAILURE);
+           } 
+       }
+       do {
+           nwrite = splice(pipefd[0], NULL, out_fd, NULL, nread, 
+                           SPLICE_F_MOVE|SPLICE_F_MORE);
+           if (nwrite == 0) continue;
+           if (nwrite < 0) {
+               if (errno == EINTR)
+                   continue;
+               else {
+                   perror("write error");
+                   exit(EXIT_FAILURE);
+               }
+           }
+           nread -= nwrite;
+       } while (nread);
+    }
+    return EXIT_SUCCESS;
+}