- /* Read the raw input file and transform it */
- filebuf = malloc(sizeof(*envptr) * filesize);
- ret = read(txt_fd, filebuf, sizeof(*envptr) * filesize);
- if (ret != sizeof(*envptr) * filesize) {
- fprintf(stderr, "Can't read the whole input file\n");
- return EXIT_FAILURE;
+
+ filebuf = mmap(NULL, sizeof(*envptr) * filesize, PROT_READ,
+ MAP_PRIVATE, txt_fd, 0);
+ if (filebuf == MAP_FAILED) {
+ fprintf(stderr, "mmap (%zu bytes) failed: %s\n",
+ sizeof(*envptr) * filesize,
+ strerror(errno));
+ fprintf(stderr, "Falling back to read()\n");
+
+ filebuf = malloc(sizeof(*envptr) * filesize);
+ ret = read(txt_fd, filebuf, sizeof(*envptr) * filesize);
+ if (ret != sizeof(*envptr) * filesize) {
+ fprintf(stderr, "Can't read the whole input file (%zu bytes): %s\n",
+ sizeof(*envptr) * filesize,
+ strerror(errno));
+
+ return EXIT_FAILURE;
+ }