/* comm -- compare two sorted files line by line. Copyright (C) 1986, 1990, 1991 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* Written by Richard Stallman and David MacKenzie. */ #ifdef HAVE_CONFIG_H #if defined (CONFIG_BROKETS) /* We use instead of "config.h" so that a compilation using -I. -I$srcdir will use ./config.h rather than $srcdir/config.h (which it would do because it found this file in $srcdir). */ #include #else #include "config.h" #endif #endif #include #include #include #include "system.h" #include "linebuffer.h" #include "version.h" #ifndef min #define min(x, y) ((x) < (y) ? (x) : (y)) #endif /* The name this program was run with. */ char *program_name; /* If nonzero, print lines that are found only in file 1. */ static int only_file_1; /* If nonzero, print lines that are found only in file 2. */ static int only_file_2; /* If nonzero, print lines that are found in both files. */ static int both; /* If non-zero, display usage information and exit. */ static int show_help; /* If non-zero, print the version on standard output then exit. */ static int show_version; static struct option const long_options[] = { {"help", no_argument, &show_help, 1}, {"version", no_argument, &show_version, 1}, {0, 0, 0, 0} }; void error (); static int compare_files (); static void writeline (); static void usage (); void main (argc, argv) int argc; char *argv[]; { int c; program_name = argv[0]; only_file_1 = 1; only_file_2 = 1; both = 1; while ((c = getopt_long (argc, argv, "123", long_options, (int *) 0)) != EOF) switch (c) { case 0: break; case '1': only_file_1 = 0; break; case '2': only_file_2 = 0; break; case '3': both = 0; break; default: usage (1); } if (show_version) { printf ("%s\n", version_string); exit (0); } if (show_help) usage (0); if (optind + 2 != argc) usage (0); exit (compare_files (argv + optind)); } /* 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. Return 0 if successful, 1 if any errors occur. */ static int compare_files (infiles) 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, ret = 0; /* Initialize the storage. */ for (i = 0; i < 2; i++) { initbuffer (&lb1[i]); thisline[i] = &lb1[i]; streams[i] = strcmp (infiles[i], "-") ? fopen (infiles[i], "r") : stdin; if (!streams[i]) { error (0, errno, "%s", infiles[i]); return 1; } thisline[i] = readline (thisline[i], streams[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 { /* Cannot use bcmp -- it only returns a boolean value. */ order = memcmp (thisline[0]->buffer, thisline[1]->buffer, min (thisline[0]->length, thisline[1]->length)); if (order == 0) order = 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] = readline (thisline[1], streams[1]); if (order <= 0) thisline[0] = readline (thisline[0], streams[0]); } /* Free all storage and close all input streams. */ for (i = 0; i < 2; i++) { free (lb1[i].buffer); if (ferror (streams[i]) || fclose (streams[i]) == EOF) { error (0, errno, "%s", infiles[i]); ret = 1; } } if (ferror (stdout) || fclose (stdout) == EOF) { error (0, errno, "write error"); ret = 1; } return ret; } /* 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 (line, stream, class) struct linebuffer *line; FILE *stream; int class; { switch (class) { case 1: if (!only_file_1) return; break; case 2: if (!only_file_2) return; /* Skip the tab stop for case 1, if we are printing case 1. */ if (only_file_1) putc ('\t', stream); break; case 3: if (!both) return; /* Skip the tab stop for case 1, if we are printing case 1. */ if (only_file_1) putc ('\t', stream); /* Skip the tab stop for case 2, if we are printing case 2. */ if (only_file_2) putc ('\t', stream); break; } fwrite (line->buffer, sizeof (char), line->length, stream); putc ('\n', stream); } static void usage (status) int status; { if (status != 0) fprintf (stderr, "Try `%s --help' for more information.\n", program_name); else { print_version("comm"); printf ("\ Usage: %s [OPTION]... LEFT_FILE RIGHT_FILE\n\ ", program_name); printf ("\ \n\ -1 suppress lines unique to left file\n\ -2 suppress lines unique to right file\n\ -3 suppress lines unique to both files\n\ --help display this help and exit\n\ --version output version information and exit\n\ "); } exit (status); }