cpio: optional support for writing cpio files in newc format.
authorDenis Vlasenko <vda.linux@googlemail.com>
Sat, 5 Apr 2008 00:07:46 +0000 (00:07 -0000)
committerDenis Vlasenko <vda.linux@googlemail.com>
Sat, 5 Apr 2008 00:07:46 +0000 (00:07 -0000)
by pascal.bellard AT ads-lu.com.

function                                             old     new   delta
cpio_main                                            247    1122    +875
cpio_pad4                                              -      58     +58
gnu_dev_major                                         66      99     +33
gnu_dev_minor                                         38      57     +19
packed_usage                                       23964   23978     +14
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 4/0 up/down: 999/0)             Total: 999 bytes

archival/Config.in
archival/cpio.c
include/usage.h

index 60c3ed2d59cd57a592507c15ed23c66c5a75fc73..28450612ed70389a174d7bf0eafa062956fede6b 100644 (file)
@@ -78,6 +78,14 @@ config CPIO
          Unless you have a specific application which requires cpio, you should
          probably say N here.
 
+config FEATURE_CPIO_O
+       bool "Support for archive creation"
+       default n
+       depends on CPIO
+       help
+         This implementation of cpio can create cpio archives in the "newc"
+         format only.
+
 config DPKG
        bool "dpkg"
        default n
index 59ae60c77267563d8677a6b36378adf21f896b2c..c17219832b93a16144828c1a7d8cf6a5dda91b4d 100644 (file)
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  *
  * Limitations:
- *             Doesn't check CRC's
- *             Only supports new ASCII and CRC formats
+ * Doesn't check CRC's
+ * Only supports new ASCII and CRC formats
  *
  */
 #include "libbb.h"
 #include "unarchive.h"
 
-#define CPIO_OPT_EXTRACT                0x01
-#define CPIO_OPT_TEST                   0x02
-#define CPIO_OPT_UNCONDITIONAL          0x04
-#define CPIO_OPT_VERBOSE                0x08
-#define CPIO_OPT_FILE                   0x10
-#define CPIO_OPT_CREATE_LEADING_DIR     0x20
-#define CPIO_OPT_PRESERVE_MTIME         0x40
+enum {
+       CPIO_OPT_EXTRACT            = (1 << 0),
+       CPIO_OPT_TEST               = (1 << 1),
+       CPIO_OPT_UNCONDITIONAL      = (1 << 2),
+       CPIO_OPT_VERBOSE            = (1 << 3),
+       CPIO_OPT_FILE               = (1 << 4),
+       CPIO_OPT_CREATE_LEADING_DIR = (1 << 5),
+       CPIO_OPT_PRESERVE_MTIME     = (1 << 6),
+       CPIO_OPT_CREATE             = (1 << 7),
+       CPIO_OPT_FORMAT             = (1 << 8),
+};
+
+#if ENABLE_FEATURE_CPIO_O
+static off_t cpio_pad4(off_t size)
+{
+       int i;
+
+       i = (- size) & 3;
+       size += i;
+       while (--i >= 0)
+               bb_putchar('\0');
+       return size;
+}
+
+/* Return value will become exit code.
+ * It's ok to exit instead of return. */
+static int cpio_o(void)
+{
+       struct name_s {
+               struct name_s *next;
+               char name[1];
+       };
+       struct inodes_s {
+               struct inodes_s *next;
+               struct name_s *names;
+               struct stat st;
+       };
+
+       struct inodes_s *links = NULL;
+       off_t bytes = 0; /* output bytes count */
+
+       while (1) {
+               const char *name;
+               char *line;
+               struct stat st;
+
+               line = xmalloc_fgetline(stdin);
+
+               if (line) {
+                       /* Strip leading "./[./]..." from the filename */
+                       name = line;
+                       while (name[0] == '.' && name[1] == '/') {
+                               while (*++name == '/')
+                                       continue;
+                       }
+                       if (!*name) { /* line is empty */
+                               free(line);
+                               continue;
+                       }
+                       if (lstat(name, &st)) {
+ abort_cpio_o:
+                               bb_simple_perror_msg_and_die(name);
+                       }
+
+                       if (!(S_ISLNK(st.st_mode) || S_ISREG(st.st_mode)))
+                               st.st_size = 0; /* paranoia */
+
+                       /* Store hardlinks for later processing, dont output them */
+                       if (!S_ISDIR(st.st_mode) && st.st_nlink > 1) {
+                               struct name_s *n;
+                               struct inodes_s *l;
+
+                               /* Do we have this hardlink remembered? */
+                               l = links;
+                               while (1) {
+                                       if (l == NULL) {
+                                               /* Not found: add new item to "links" list */
+                                               l = xzalloc(sizeof(*l));
+                                               l->st = st;
+                                               l->next = links;
+                                               links = l;
+                                               break;
+                                       }
+                                       if (l->st.st_ino == st.st_ino) {
+                                               /* found */
+                                               break;
+                                       }
+                                       l = l->next;
+                               }
+                               /* Add new name to "l->names" list */
+                               n = xmalloc(sizeof(*n) + strlen(name));
+                               strcpy(n->name, name);
+                               n->next = l->names;
+                               l->names = n;
+
+                               free(line);
+                               continue;
+                       }
+
+               } else { /* line == NULL: EOF */
+ next_link:
+                       if (links) {
+                               /* Output hardlink's data */
+                               st = links->st;
+                               name = links->names->name;
+                               links->names = links->names->next;
+                               /* GNU cpio is reported to emit file data
+                                * only for the last instance. Mimic that. */
+                               if (links->names == NULL)
+                                       links = links->next;
+                               else
+                                       st.st_size = 0;
+                               /* NB: we leak links->names and/or links,
+                                * this is intended (we exit soon anyway) */
+                       } else {
+                               /* If no (more) hardlinks to output,
+                                * output "trailer" entry */
+                               name = "TRAILER!!!";
+                               /* st.st_size == 0 is a must, but for uniformity
+                                * in the output, we zero out everything */
+                               memset(&st, 0, sizeof(st));
+                               /* st.st_nlink = 1; - GNU cpio does this */
+                       }
+               }
+
+               bytes += printf("070701"
+                               "%08X%08X%08X%08X%08X%08X%08X"
+                               "%08X%08X%08X%08X" /* GNU cpio uses uppercase hex */
+                               /* strlen+1: */ "%08X"
+                               /* chksum: */   "00000000" /* (only for "070702" files) */
+                               /* name,NUL: */ "%s%c",
+                               (unsigned)(uint32_t) st.st_ino,
+                               (unsigned)(uint32_t) st.st_mode,
+                               (unsigned)(uint32_t) st.st_uid,
+                               (unsigned)(uint32_t) st.st_gid,
+                               (unsigned)(uint32_t) st.st_nlink,
+                               (unsigned)(uint32_t) st.st_mtime,
+                               (unsigned)(uint32_t) st.st_size,
+                               (unsigned)(uint32_t) major(st.st_dev),
+                               (unsigned)(uint32_t) minor(st.st_dev),
+                               (unsigned)(uint32_t) major(st.st_rdev),
+                               (unsigned)(uint32_t) minor(st.st_rdev),
+                               (unsigned)(strlen(name) + 1),
+                               name, '\0');
+               bytes = cpio_pad4(bytes);
+
+               if (st.st_size) {
+                       if (S_ISLNK(st.st_mode)) {
+                               char *lpath = xmalloc_readlink_or_warn(name);
+                               if (!lpath)
+                                       goto abort_cpio_o;
+                               bytes += printf("%s", lpath);
+                               free(lpath);
+                       } else { /* S_ISREG */
+                               int fd = xopen(name, O_RDONLY);
+                               fflush(stdout);
+                               /* We must abort if file got shorter too! */
+                               if (bb_copyfd_size(fd, STDOUT_FILENO, st.st_size) != st.st_size) {
+                                       bb_error_msg_and_die("I/O error, of file '%s' was truncated", name);
+                               }
+                               bytes += st.st_size;
+                               close(fd);
+                       }
+                       bytes = cpio_pad4(bytes);
+               }
+
+               if (!line) {
+                       if (links)
+                               goto next_link;
+                       /* TODO: GNU cpio pads trailer to 512 bytes, do we want that? */
+                       return EXIT_SUCCESS;
+               }
+
+               free(line);
+       } /* end of "while (1)" */
+}
+#endif
 
 int cpio_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int cpio_main(int argc, char **argv)
+int cpio_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
        archive_handle_t *archive_handle;
-       char *cpio_filename = NULL;
+       char *cpio_filename;
+#if ENABLE_FEATURE_CPIO_O
+       const char *cpio_fmt = "";
+#endif
        unsigned opt;
 
-       /* Initialise */
+       /* Initialize */
        archive_handle = init_handle();
        archive_handle->src_fd = STDIN_FILENO;
        archive_handle->seek = seek_by_read;
        archive_handle->flags = ARCHIVE_EXTRACT_NEWER | ARCHIVE_PRESERVE_DATE;
 
+#if ENABLE_FEATURE_CPIO_O
+       opt = getopt32(argv, "ituvF:dmoH:", &cpio_filename, &cpio_fmt);
+
+       if (opt & CPIO_OPT_CREATE) {
+               if (*cpio_fmt != 'n')
+                       bb_show_usage();
+               if (opt & CPIO_OPT_FILE) {
+                       fclose(stdout);
+                       stdout = fopen(cpio_filename, "w");
+                       /* Paranoia: I don't trust libc that much */
+                       xdup2(fileno(stdout), STDOUT_FILENO);
+               }
+               return cpio_o();
+       }
+#else
        opt = getopt32(argv, "ituvF:dm", &cpio_filename);
+#endif
+       argv += optind;
 
        /* One of either extract or test options must be given */
        if ((opt & (CPIO_OPT_TEST | CPIO_OPT_EXTRACT)) == 0) {
@@ -63,7 +253,7 @@ int cpio_main(int argc, char **argv)
                        archive_handle->action_header = header_list;
                }
        }
-       if (cpio_filename) { /* CPIO_OPT_FILE */
+       if (opt & CPIO_OPT_FILE) { /* -F */
                archive_handle->src_fd = xopen(cpio_filename, O_RDONLY);
                archive_handle->seek = seek_by_jump;
        }
@@ -71,13 +261,14 @@ int cpio_main(int argc, char **argv)
                archive_handle->flags |= ARCHIVE_CREATE_LEADING_DIRS;
        }
 
-       while (optind < argc) {
+       while (*argv) {
                archive_handle->filter = filter_accept_list;
-               llist_add_to(&(archive_handle->accept), argv[optind]);
-               optind++;
+               llist_add_to(&(archive_handle->accept), *argv);
+               argv++;
        }
 
-       while (get_header_cpio(archive_handle) == EXIT_SUCCESS);
+       while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
+               continue;
 
        return EXIT_SUCCESS;
 }
index 529a228ec88f118f412fe22c70bde5d9eaf3c741..0849c68315070073904cb9b4ddb50dd78b9b9a00 100644 (file)
      "\n       -l,-s   Create (sym)links" \
 
 #define cpio_trivial_usage \
-       "-[dimtuv][F cpiofile]"
+       "-[dim" USE_FEATURE_CPIO_O("o") "tuv][F cpiofile]" \
+       USE_FEATURE_CPIO_O( "[H newc]" ) 
 #define cpio_full_usage \
-       "Extract or list files from a cpio archive\n" \
+       "Extract or list files from a cpio archive" \
+       USE_FEATURE_CPIO_O( ", or create a cpio archive" ) \
+     "\n" \
        "Main operation mode:" \
      "\n       d       Make leading directories" \
      "\n       i       Extract" \
      "\n       m       Preserve mtime" \
+       USE_FEATURE_CPIO_O( \
+     "\n       o       Create" \
+     "\n       H newc  Define format" \
+       ) \
      "\n       t       List" \
      "\n       v       Verbose" \
      "\n       u       Unconditional overwrite" \