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Diffstat (limited to 'src/comm.c')
| -rw-r--r-- | src/comm.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/src/comm.c b/src/comm.c new file mode 100644 index 0000000..9b7e03f --- /dev/null +++ b/src/comm.c @@ -0,0 +1,285 @@ +/* comm -- compare two sorted files line by line. + Copyright (C) 86, 90, 91, 1995-2005 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +/* Written by Richard Stallman and David MacKenzie. */ + +#include <config.h> + +#include <getopt.h> +#include <sys/types.h> +#include "system.h" +#include "linebuffer.h" +#include "error.h" +#include "hard-locale.h" +#include "quote.h" +#include "stdio--.h" +#include "xmemcoll.h" + +/* The official name of this program (e.g., no `g' prefix). */ +#define PROGRAM_NAME "comm" + +#define AUTHORS "Richard Stallman", "David MacKenzie" + +/* Undefine, to avoid warning about redefinition on some systems. */ +#undef min +#define min(x, y) ((x) < (y) ? (x) : (y)) + +/* The name this program was run with. */ +char *program_name; + +/* True if the LC_COLLATE locale is hard. */ +static bool hard_LC_COLLATE; + +/* If true, print lines that are found only in file 1. */ +static bool only_file_1; + +/* If true, print lines that are found only in file 2. */ +static bool only_file_2; + +/* If true, print lines that are found in both files. */ +static bool both; + +static struct option const long_options[] = +{ + {GETOPT_HELP_OPTION_DECL}, + {GETOPT_VERSION_OPTION_DECL}, + {NULL, 0, NULL, 0} +}; + + + +void +usage (int status) +{ + if (status != EXIT_SUCCESS) + fprintf (stderr, _("Try `%s --help' for more information.\n"), + program_name); + else + { + printf (_("\ +Usage: %s [OPTION]... FILE1 FILE2\n\ +"), + program_name); + fputs (_("\ +Compare sorted files FILE1 and FILE2 line by line.\n\ +"), stdout); + fputs (_("\ +\n\ +With no options, produce three-column output. Column one contains\n\ +lines unique to FILE1, column two contains lines unique to FILE2,\n\ +and column three contains lines common to both files.\n\ +"), stdout); + fputs (_("\ +\n\ + -1 suppress lines unique to FILE1\n\ + -2 suppress lines unique to FILE2\n\ + -3 suppress lines that appear in both files\n\ +"), stdout); + fputs (HELP_OPTION_DESCRIPTION, stdout); + fputs (VERSION_OPTION_DESCRIPTION, stdout); + printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT); + } + exit (status); +} + +/* Output the line in linebuffer LINE to stream STREAM + provided the switches say it should be output. + CLASS is 1 for a line found only in file 1, + 2 for a line only in file 2, 3 for a line in both. */ + +static void +writeline (const struct linebuffer *line, FILE *stream, int class) +{ + switch (class) + { + case 1: + if (!only_file_1) + return; + break; + + case 2: + if (!only_file_2) + return; + /* Print a TAB if we are printing lines from file 1. */ + if (only_file_1) + putc ('\t', stream); + break; + + case 3: + if (!both) + return; + /* Print a TAB if we are printing lines from file 1. */ + if (only_file_1) + putc ('\t', stream); + /* Print a TAB if we are printing lines from file 2. */ + if (only_file_2) + putc ('\t', stream); + break; + } + + fwrite (line->buffer, sizeof (char), line->length, stream); +} + +/* Compare INFILES[0] and INFILES[1]. + If either is "-", use the standard input for that file. + Assume that each input file is sorted; + merge them and output the result. */ + +static void +compare_files (char **infiles) +{ + /* For each file, we have one linebuffer in lb1. */ + struct linebuffer lb1[2]; + + /* thisline[i] points to the linebuffer holding the next available line + in file i, or is NULL if there are no lines left in that file. */ + struct linebuffer *thisline[2]; + + /* streams[i] holds the input stream for file i. */ + FILE *streams[2]; + + int i; + + /* Initialize the storage. */ + for (i = 0; i < 2; i++) + { + initbuffer (&lb1[i]); + thisline[i] = &lb1[i]; + streams[i] = (STREQ (infiles[i], "-") ? stdin : fopen (infiles[i], "r")); + if (!streams[i]) + error (EXIT_FAILURE, errno, "%s", infiles[i]); + + thisline[i] = readlinebuffer (thisline[i], streams[i]); + if (ferror (streams[i])) + error (EXIT_FAILURE, errno, "%s", infiles[i]); + } + + while (thisline[0] || thisline[1]) + { + int order; + + /* Compare the next available lines of the two files. */ + + if (!thisline[0]) + order = 1; + else if (!thisline[1]) + order = -1; + else + { + if (hard_LC_COLLATE) + order = xmemcoll (thisline[0]->buffer, thisline[0]->length - 1, + thisline[1]->buffer, thisline[1]->length - 1); + else + { + size_t len = min (thisline[0]->length, thisline[1]->length) - 1; + order = memcmp (thisline[0]->buffer, thisline[1]->buffer, len); + if (order == 0) + order = (thisline[0]->length < thisline[1]->length + ? -1 + : thisline[0]->length != thisline[1]->length); + } + } + + /* Output the line that is lesser. */ + if (order == 0) + writeline (thisline[1], stdout, 3); + else if (order > 0) + writeline (thisline[1], stdout, 2); + else + writeline (thisline[0], stdout, 1); + + /* Step the file the line came from. + If the files match, step both files. */ + if (order >= 0) + { + thisline[1] = readlinebuffer (thisline[1], streams[1]); + if (ferror (streams[1])) + error (EXIT_FAILURE, errno, "%s", infiles[1]); + } + if (order <= 0) + { + thisline[0] = readlinebuffer (thisline[0], streams[0]); + if (ferror (streams[0])) + error (EXIT_FAILURE, errno, "%s", infiles[0]); + } + } + + for (i = 0; i < 2; i++) + if (fclose (streams[i]) != 0) + error (EXIT_FAILURE, errno, "%s", infiles[i]); +} + +int +main (int argc, char **argv) +{ + int c; + + initialize_main (&argc, &argv); + program_name = argv[0]; + setlocale (LC_ALL, ""); + bindtextdomain (PACKAGE, LOCALEDIR); + textdomain (PACKAGE); + hard_LC_COLLATE = hard_locale (LC_COLLATE); + + atexit (close_stdout); + + only_file_1 = true; + only_file_2 = true; + both = true; + + while ((c = getopt_long (argc, argv, "123", long_options, NULL)) != -1) + switch (c) + { + case '1': + only_file_1 = false; + break; + + case '2': + only_file_2 = false; + break; + + case '3': + both = false; + break; + + case_GETOPT_HELP_CHAR; + + case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS); + + default: + usage (EXIT_FAILURE); + } + + if (argc - optind < 2) + { + if (argc <= optind) + error (0, 0, _("missing operand")); + else + error (0, 0, _("missing operand after %s"), quote (argv[argc - 1])); + usage (EXIT_FAILURE); + } + + if (2 < argc - optind) + { + error (0, 0, _("extra operand %s"), quote (argv[optind + 2])); + usage (EXIT_FAILURE); + } + + compare_files (argv + optind); + + exit (EXIT_SUCCESS); +} |