diff options
| -rw-r--r-- | src/od.c | 386 |
1 files changed, 187 insertions, 199 deletions
@@ -214,11 +214,13 @@ static size_t bytes_per_block; It differs from *file_list only when *file_list is "-". */ static char const *input_filename; -/* A NULL-terminated list of the file-arguments from the command line. - If no file-arguments were specified, this variable is initialized - to { "-", NULL }. */ +/* A NULL-terminated list of the file-arguments from the command line. */ static char const *const *file_list; +/* Initializer for file_list if no file-arguments + were specified on the command line. */ +static char const *const default_file_list[] = {"-", NULL}; + /* The input stream associated with the current file. */ static FILE *in_stream; @@ -271,13 +273,15 @@ Usage: %s [OPTION]... [FILE]...\n\ or: %s --traditional [FILE] [[+]OFFSET [[+]LABEL]]\n\ "), program_name, program_name); - printf (_("\ -Write an unambiguous representation, octal bytes by default, of FILE\n\ -to standard output. With no FILE, or when FILE is -, read standard input.\n\ + printf (_("\n\ +Write an unambiguous representation, octal bytes by default,\n\ +of FILE to standard output. With more than one FILE argument,\n\ +concatenate them in the listed order to form the input.\n\ +With no FILE, or when FILE is -, read standard input.\n\ \n\ -A, --address-radix=RADIX decide how file offsets are printed\n\ - -j, --skip-bytes=BYTES skip BYTES input bytes first on each file\n\ - -N, --read-bytes=BYTES limit dump to BYTES input bytes per file\n\ + -j, --skip-bytes=BYTES skip BYTES input bytes first\n\ + -N, --read-bytes=BYTES limit dump to BYTES input bytes\n\ -s, --strings[=BYTES] output strings of at least BYTES graphic chars\n\ -t, --format=TYPE select output format or formats\n\ -v, --output-duplicates do not use * to mark line suppression\n\ @@ -892,6 +896,88 @@ this system doesn't provide a %lu-byte floating point type"), s_orig, size); return 0; } +/* Given a list of one or more input filenames FILE_LIST, set the global + file pointer IN_STREAM and the global string INPUT_FILENAME to the + first one that can be successfully opened. Modify FILE_LIST to + reference the next filename in the list. A file name of "-" is + interpreted as standard input. If any file open fails, give an error + message and return nonzero. */ + +static int +open_next_file (void) +{ + int err = 0; + + do + { + input_filename = *file_list; + if (input_filename == NULL) + return err; + ++file_list; + + if (STREQ (input_filename, "-")) + { + input_filename = _("standard input"); + in_stream = stdin; + have_read_stdin = 1; + } + else + { + in_stream = fopen (input_filename, "r"); + if (in_stream == NULL) + { + error (0, errno, "%s", input_filename); + err = 1; + } + } + } + while (in_stream == NULL); + + if (limit_bytes_to_format && !flag_dump_strings) + setbuf (in_stream, NULL); + SET_BINARY (fileno (in_stream)); + + return err; +} + +/* Test whether there have been errors on in_stream, and close it if + it is not standard input. Return nonzero if there has been an error + on in_stream or stdout; return zero otherwise. This function will + report more than one error only if both a read and a write error + have occurred. */ + +static int +check_and_close (void) +{ + int err = 0; + + if (in_stream != NULL) + { + if (ferror (in_stream)) + { + error (0, errno, "%s", input_filename); + if (in_stream != stdin) + fclose (in_stream); + err = 1; + } + else if (in_stream != stdin && fclose (in_stream) == EOF) + { + error (0, errno, "%s", input_filename); + err = 1; + } + + in_stream = NULL; + } + + if (ferror (stdout)) + { + error (0, errno, _("standard output")); + err = 1; + } + + return err; +} + /* Decode the POSIX-style od format string S. Append the decoded representation to the global array SPEC, reallocating SPEC if necessary. Return zero if S is valid, nonzero otherwise. */ @@ -933,42 +1019,20 @@ decode_format_string (const char *s) file pointer IN_STREAM to position N_SKIP in the concatenation of those files. If any file operation fails or if there are fewer than N_SKIP bytes in the combined input, give an error message and return - nonzero. When possible, use seek- rather than read operations to - advance IN_STREAM. A file name of "-" is interpreted as standard - input. */ + nonzero. When possible, use seek rather than read operations to + advance IN_STREAM. */ static int skip (off_t n_skip) { - int err; + int err = 0; - err = 0; - for ( /* empty */ ; *file_list != NULL; ++file_list) + if (n_skip == 0) + return 0; + + while (in_stream != NULL) /* EOF. */ { struct stat file_stats; - int j; - - if (STREQ (*file_list, "-")) - { - input_filename = _("standard input"); - in_stream = stdin; - have_read_stdin = 1; - } - else - { - input_filename = *file_list; - in_stream = fopen (input_filename, "r"); - if (in_stream == NULL) - { - error (0, errno, "%s", input_filename); - err = 1; - continue; - } - } - SET_BINARY (fileno (in_stream)); - - if (n_skip == 0) - break; /* First try seeking. For large offsets, this extra work is worthwhile. If the offset is below some threshold it may be @@ -980,58 +1044,60 @@ skip (off_t n_skip) Try to do that by getting file's size using fstat. But that will work only for regular files. */ - if (fstat (fileno (in_stream), &file_stats)) + if (fstat (fileno (in_stream), &file_stats) == 0) { - error (0, errno, "%s", input_filename); - err = 1; - continue; - } + /* The st_size field is valid only for regular files + (and for symbolic links, which cannot occur here). + If the number of bytes left to skip is at least + as large as the size of the current file, we can + decrement n_skip and go on to the next file. */ - /* The st_size field is valid only for regular files - (and for symbolic links, which cannot occur here). - If the number of bytes left to skip is at least as large as - the size of the current file, we can decrement - n_skip and go on to the next file. */ - if (S_ISREG (file_stats.st_mode)) - { - if (file_stats.st_size <= n_skip) + if (S_ISREG (file_stats.st_mode) && file_stats.st_size <= n_skip) { n_skip -= file_stats.st_size; - if (in_stream != stdin && fclose (in_stream) == EOF) - { - error (0, errno, "%s", input_filename); - err = 1; - } - continue; } + + /* If the number of bytes left to skip is less than the size + of the current file, try seeking to the correct offset. */ + + else if (S_ISREG (file_stats.st_mode) && + fseek (in_stream, n_skip, SEEK_CUR) == 0) + { + n_skip = 0; + } + + /* If seek didn't work or wasn't attempted, + position the file pointer by reading. */ + else { - if (0 <= lseek (fileno (in_stream), n_skip, SEEK_CUR)) + char buf[BUFSIZ]; + size_t n_bytes_read, n_bytes_to_read = BUFSIZ; + + while (0 < n_skip) { - n_skip = 0; - break; + if (n_skip < n_bytes_to_read) + n_bytes_to_read = n_skip; + n_bytes_read = fread (buf, 1, n_bytes_to_read, in_stream); + n_skip -= n_bytes_read; + if (n_bytes_read != n_bytes_to_read) + break; } } - } - /* Seek didn't work or wasn't attempted; position the file pointer - by reading. */ + if (n_skip == 0) + break; + } - for (j = n_skip / BUFSIZ; 0 <= j; j--) + else /* cannot fstat() file */ { - char buf[BUFSIZ]; - size_t n_bytes_to_read = (0 < j - ? BUFSIZ - : n_skip % BUFSIZ); - size_t n_bytes_read; - n_bytes_read = fread (buf, 1, n_bytes_to_read, in_stream); - n_skip -= n_bytes_read; - if (n_bytes_read != n_bytes_to_read) - break; + error (0, errno, "%s", input_filename); + err = 1; } - if (n_skip == 0) - break; + err |= check_and_close (); + + err |= open_next_file (); } if (n_skip != 0) @@ -1162,119 +1228,57 @@ write_block (off_t current_offset, off_t n_bytes, first = 0; } -/* Test whether there have been errors on in_stream, and close it if - it is not standard input. Return nonzero if there has been an error - on in_stream or stdout; return zero otherwise. This function will - report more than one error only if both a read and a write error - have occurred. */ - -static int -check_and_close (void) -{ - int err; - - err = 0; - if (ferror (in_stream)) - { - error (0, errno, "%s", input_filename); - if (in_stream != stdin) - fclose (in_stream); - err = 1; - } - else if (in_stream != stdin && fclose (in_stream) == EOF) - { - error (0, errno, "%s", input_filename); - err = 1; - } - - if (ferror (stdout)) - { - error (0, errno, _("standard output")); - err = 1; - } - - return err; -} - /* Read a single byte into *C from the concatenation of the input files named in the global array FILE_LIST. On the first call to this function, the global variable IN_STREAM is expected to be an open - stream associated with the input file *FILE_LIST. If IN_STREAM is - at end-of-file, close it and update the global variables IN_STREAM, - FILE_LIST, and INPUT_FILENAME so they correspond to the next file in - the list. Then try to read a byte from the newly opened file. - Repeat if necessary until *FILE_LIST is NULL. When EOF is reached - for the last file in FILE_LIST, set *C to EOF and return. Subsequent - calls do likewise. The return value is nonzero if any errors - occured, zero otherwise. */ + stream associated with the input file INPUT_FILENAME. If IN_STREAM + is at end-of-file, close it and update the global variables IN_STREAM + and INPUT_FILENAME so they correspond to the next file in the list. + Then try to read a byte from the newly opened file. Repeat if + necessary until EOF is reached for the last file in FILE_LIST, then + set *C to EOF and return. Subsequent calls do likewise. The return + value is nonzero if any errors occured, zero otherwise. */ static int read_char (int *c) { - int err; + int err = 0; - if (*file_list == NULL) - { - *c = EOF; - return 0; - } + *c = EOF; - err = 0; - while (1) + while (in_stream != NULL) /* EOF. */ { *c = fgetc (in_stream); if (*c != EOF) - return err; + break; err |= check_and_close (); - do - { - ++file_list; - if (*file_list == NULL) - return err; - - if (STREQ (*file_list, "-")) - { - input_filename = _("standard input"); - in_stream = stdin; - have_read_stdin = 1; - } - else - { - input_filename = *file_list; - in_stream = fopen (input_filename, "r"); - if (in_stream == NULL) - { - error (0, errno, "%s", input_filename); - err = 1; - } - } - SET_BINARY (fileno (in_stream)); - } - while (in_stream == NULL); + err |= open_next_file (); } + + return err; } /* Read N bytes into BLOCK from the concatenation of the input files named in the global array FILE_LIST. On the first call to this function, the global variable IN_STREAM is expected to be an open - stream associated with the input file *FILE_LIST. On subsequent - calls, if *FILE_LIST is NULL, don't modify BLOCK and return zero. - If all N bytes cannot be read from IN_STREAM, close IN_STREAM and - update the global variables IN_STREAM, FILE_LIST, and INPUT_FILENAME. - Then try to read the remaining bytes from the newly opened file. - Repeat if necessary until *FILE_LIST is NULL. Set *N_BYTES_IN_BUFFER - to the number of bytes read. If an error occurs, it will be detected - through ferror when the stream is about to be closed. If there is an - error, give a message but continue reading as usual and return nonzero. - Otherwise return zero. */ + stream associated with the input file INPUT_FILENAME. If all N + bytes cannot be read from IN_STREAM, close IN_STREAM and update + the global variables IN_STREAM and INPUT_FILENAME. Then try to + read the remaining bytes from the newly opened file. Repeat if + necessary until EOF is reached for the last file in FILE_LIST. + On subsequent calls, don't modify BLOCK and return zero. Set + *N_BYTES_IN_BUFFER to the number of bytes read. If an error occurs, + it will be detected through ferror when the stream is about to be + closed. If there is an error, give a message but continue reading + as usual and return nonzero. Otherwise return zero. */ static int read_block (size_t n, char *block, size_t *n_bytes_in_buffer) { - int err; + int err = 0; assert (0 < n && n <= bytes_per_block); @@ -1283,11 +1287,7 @@ read_block (size_t n, char *block, size_t *n_bytes_in_buffer) if (n == 0) return 0; - if (*file_list == NULL) - return 0; /* EOF. */ - - err = 0; - while (1) + while (in_stream != NULL) /* EOF. */ { size_t n_needed; size_t n_read; @@ -1298,36 +1298,14 @@ read_block (size_t n, char *block, size_t *n_bytes_in_buffer) *n_bytes_in_buffer += n_read; if (n_read == n_needed) - return err; + break; err |= check_and_close (); - do - { - ++file_list; - if (*file_list == NULL) - return err; - - if (STREQ (*file_list, "-")) - { - input_filename = _("standard input"); - in_stream = stdin; - have_read_stdin = 1; - } - else - { - input_filename = *file_list; - in_stream = fopen (input_filename, "r"); - if (in_stream == NULL) - { - error (0, errno, "%s", input_filename); - err = 1; - } - } - SET_BINARY (fileno (in_stream)); - } - while (in_stream == NULL); + err |= open_next_file (); } + + return err; } /* Return the least common multiple of the sizes associated @@ -1475,7 +1453,7 @@ dump (void) format_address (current_offset, '\n'); - if (limit_bytes_to_format && current_offset > end_offset) + if (limit_bytes_to_format && current_offset >= end_offset) err |= check_and_close (); return err; @@ -1593,7 +1571,7 @@ dump_strings (void) } /* We reach this point only if we search through - (max_bytes_to_format - string_min) bytes before reachine EOF. */ + (max_bytes_to_format - string_min) bytes before reaching EOF. */ free (buf); @@ -1913,17 +1891,27 @@ it must be one character from [doxn]"), } if (n_files > 0) - file_list = (char const *const *) &argv[optind]; + { + /* Set the global pointer FILE_LIST so that it + references the first file-argument on the command-line. */ + + file_list = (char const *const *) &argv[optind]; + } else { - /* If no files were listed on the command line, set up the - global array FILE_LIST so that it contains the null-terminated - list of one name: "-". */ - static char const *const default_file_list[] = {"-", NULL}; + /* No files were listed on the command line. + Set the global pointer FILE_LIST so that it + references the null-terminated list of one name: "-". */ file_list = default_file_list; } + /* open the first input file */ + err |= open_next_file (); + if (in_stream == NULL) + goto cleanup; + + /* skip over any unwanted header bytes */ err |= skip (n_bytes_to_skip); if (in_stream == NULL) goto cleanup; |