/* vi: set sw=4 ts=4: */ /* * Mini comm implementation for busybox * * Copyright (C) 2005 by Robert Sullivan <cogito.ergo.cogito@gmail.com> * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ #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) { if (class == 0) { if (!only_file_1) return; } else if (class == 1) { if (!only_file_2) return; if (only_file_1) putchar('\t'); } else /*if (class == 2)*/ { if (!both) return; if (only_file_1) putchar('\t'); if (only_file_2) putchar('\t'); } fputs(line, stdout); } /* This is the real core of the program - lines are compared here */ static void cmp_files(char **infiles) { #define LINE_LEN 100 #define BB_EOF_0 0x1 #define BB_EOF_1 0x2 char thisline[2][LINE_LEN]; FILE *streams[2]; int i; for (i = 0; i < 2; ++i) { streams[i] = ((infiles[i][0] == '=' && infiles[i][1]) ? stdin : xfopen(infiles[i], "r")); fgets(thisline[i], LINE_LEN, streams[i]); } while (*thisline[0] || *thisline[1]) { int order = 0; i = 0; if (feof(streams[0])) i |= BB_EOF_0; if (feof(streams[1])) i |= BB_EOF_1; if (!*thisline[0]) order = 1; else if (!*thisline[1]) order = -1; else { int tl0_len, tl1_len; tl0_len = strlen(thisline[0]); tl1_len = strlen(thisline[1]); 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 && !i) writeline(thisline[1], 2); else if (order > 0 && !(i & BB_EOF_1)) writeline(thisline[1], 1); else if (order < 0 && !(i & BB_EOF_0)) writeline(thisline[0], 0); if (i & BB_EOF_0 & BB_EOF_1) { break; } else if (i) { i = (i & BB_EOF_0 ? 1 : 0); while (!feof(streams[i])) { if ((order < 0 && i) || (order > 0 && !i)) writeline(thisline[i], i); fgets(thisline[i], LINE_LEN, streams[i]); } break; } else { if (order >= 0) fgets(thisline[1], LINE_LEN, streams[1]); if (order <= 0) fgets(thisline[0], LINE_LEN, streams[0]); } } fclose(streams[0]); fclose(streams[1]); } int comm_main(int argc, char **argv) { unsigned long flags; flags = bb_getopt_ulflags(argc, argv, "123"); if (optind + 2 != argc) bb_show_usage(); only_file_1 = !(flags & COMM_OPT_1); only_file_2 = !(flags & COMM_OPT_2); both = !(flags & COMM_OPT_3); cmp_files(argv + optind); exit(EXIT_SUCCESS); }