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Diffstat (limited to 'coreutils/comm.c')
| -rw-r--r-- | coreutils/comm.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/coreutils/comm.c b/coreutils/comm.c new file mode 100644 index 0000000..3e81a5a --- /dev/null +++ b/coreutils/comm.c @@ -0,0 +1,155 @@ +/* vi: set sw=4 ts=4: */ +/* + * Mini comm implementation for busybox + * + * Copyright (C) 2005 by Robert Sullivan <cogito.ergo.cogito@gmail.com> + * + * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA + * 02111-1307 USA + * + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include "busybox.h" + +#define COMM_OPT_1 0x01 +#define COMM_OPT_2 0x02 +#define COMM_OPT_3 0x04 + +/* These three variables control behaviour if non-zero */ + +static int only_file_1; +static int only_file_2; +static int both; + +/* writeline outputs the input given, appropriately aligned according to class */ +static void writeline (char *line, int class) { + switch (class) { + case 1: if (!only_file_1) + return; + break; + case 2: if (!only_file_2) + return; + if (only_file_1) + putchar('\t'); + break; + case 3: if (!both) + return; + if (only_file_1) + putchar('\t'); + if (only_file_2) + putchar('\t'); + break; + } + fputs(line, stdout); +} + +/* This is the real core of the program - lines are compared here */ +static int cmp_files(char **infiles) { + + char thisline[2][100]; + FILE *streams[2]; + int i = 0; + + for (i = 0; i < 2; i++) { + streams[i] = (strcmp(infiles[i], "=") == 0 ? stdin : fopen(infiles[i], "r")); + fgets(thisline[i], 100, streams[i]); + } + + while (thisline[0] || thisline[1]) { + + int order = 0; + int tl0_len = strlen(thisline[0]); + int tl1_len = strlen(thisline[1]); + if (!thisline[0]) + order = 1; + else if (!thisline[1]) + order = -1; + else { + order = memcmp(thisline[0], thisline[1], tl0_len < tl1_len ? tl0_len : tl1_len); + if (!order) + order = tl0_len < tl1_len ? -1 : tl0_len != tl1_len; + } + + if ((order == 0) && (!feof(streams[0])) && (!feof(streams[1]))) + writeline(thisline[1], 3); + else if ((order > 0) && (!feof(streams[1]))) + writeline(thisline[1], 2); + else if ((order < 0) && (!feof(streams[0]))) + writeline(thisline[0], 1); + + if (feof(streams[0]) && feof(streams[1])) { + fclose(streams[0]); + fclose(streams[1]); + break; + } + else if (feof(streams[0])) { + + while (!feof(streams[1])) { + if (order < 0) + writeline(thisline[1], 2); + fgets(thisline[1], 100, streams[1]); + } + fclose(streams[0]); + fclose(streams[1]); + break; + } + else if (feof(streams[1])) { + + while (!feof(streams[0])) { + if (order > 0) + writeline(thisline[0], 1); + fgets(thisline[0], 100, streams[0]); + } + fclose(streams[0]); + fclose(streams[1]); + break; + } + else { + if (order >= 0) + fgets(thisline[1], 100, streams[1]); + if (order <= 0) + fgets(thisline[0], 100, streams[0]); + } + } + + return 0; +} + +int comm_main (int argc, char **argv) { + + unsigned long opt; + only_file_1 = 1; + only_file_2 = 1; + both = 1; + + opt = bb_getopt_ulflags(argc, argv, "123"); + + if ((opt & 0x80000000UL) || (optind == argc)) { + bb_show_usage(); + } + + if (opt & COMM_OPT_1) + only_file_1 = 0; + if (opt & COMM_OPT_2) + only_file_2 = 0; + if (opt & COMM_OPT_3) + both = 0; + + exit(cmp_files(argv + optind) == 0 ? EXIT_SUCCESS : EXIT_FAILURE); +} |