/* $OpenBSD: diffreg.c,v 1.23 2003/06/27 20:28:13 tedu Exp $ */ /* * Copyright (C) Caldera International Inc. 2001-2002. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code and documentation must retain the above * copyright notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed or owned by Caldera * International, Inc. * 4. Neither the name of Caldera International, Inc. nor the names of other * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA * INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE FOR ANY DIRECT, * INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include "diff.h" #include "pathnames.h" #if 0 static char const sccsid[] = "@(#)diffreg.c 4.21 4/6/90"; #endif /* * diff - compare two files. */ /* * Uses an algorithm due to Harold Stone, which finds * a pair of longest identical subsequences in the two * files. * * The major goal is to generate the match vector J. * J[i] is the index of the line in file1 corresponding * to line i file0. J[i] = 0 if there is no * such line in file1. * * Lines are hashed so as to work in core. All potential * matches are located by sorting the lines of each file * on the hash (called ``value''). In particular, this * collects the equivalence classes in file1 together. * Subroutine equiv replaces the value of each line in * file0 by the index of the first element of its * matching equivalence in (the reordered) file1. * To save space equiv squeezes file1 into a single * array member in which the equivalence classes * are simply concatenated, except that their first * members are flagged by changing sign. * * Next the indices that point into member are unsorted into * array class according to the original order of file0. * * The cleverness lies in routine stone. This marches * through the lines of file0, developing a vector klist * of "k-candidates". At step i a k-candidate is a matched * pair of lines x,y (x in file0 y in file1) such that * there is a common subsequence of length k * between the first i lines of file0 and the first y * lines of file1, but there is no such subsequence for * any smaller y. x is the earliest possible mate to y * that occurs in such a subsequence. * * Whenever any of the members of the equivalence class of * lines in file1 matable to a line in file0 has serial number * less than the y of some k-candidate, that k-candidate * with the smallest such y is replaced. The new * k-candidate is chained (via pred) to the current * k-1 candidate so that the actual subsequence can * be recovered. When a member has serial number greater * that the y of all k-candidates, the klist is extended. * At the end, the longest subsequence is pulled out * and placed in the array J by unravel * * With J in hand, the matches there recorded are * check'ed against reality to assure that no spurious * matches have crept in due to hashing. If they have, * they are broken, and "jackpot" is recorded--a harmless * matter except that a true match for a spuriously * mated line may now be unnecessarily reported as a change. * * Much of the complexity of the program comes simply * from trying to minimize core utilization and * maximize the range of doable problems by dynamically * allocating what is needed and reusing what is not. * The core requirements for problems larger than somewhat * are (in words) 2*length(file0) + length(file1) + * 3*(number of k-candidates installed), typically about * 6n words for files of length n. */ #define prints(s) fputs(s,stdout) FILE *input[2]; struct cand { int x; int y; int pred; } cand; struct line { int serial; int value; } *file[2]; int len[2]; struct line *sfile[2]; /* shortened by pruning common prefix and suffix */ int slen[2]; int pref, suff; /* length of prefix and suffix */ int *class; /* will be overlaid on file[0] */ int *member; /* will be overlaid on file[1] */ int *klist; /* will be overlaid on file[0] after class */ struct cand *clist; /* merely a free storage pot for candidates */ int clen = 0; int *J; /* will be overlaid on class */ long *ixold; /* will be overlaid on klist */ long *ixnew; /* will be overlaid on file[1] */ u_char *chrtran; /* translation table for case-folding */ static void fetch(long *, int, int, FILE *, char *, int); static void output(void); static void check(void); static void range(int, int, char *); static void dump_context_vec(void); static void dump_unified_vec(void); static void prepare(int, FILE *); static void prune(void); static void equiv(struct line *, int, struct line *, int, int *); static void unravel(int); static void unsort(struct line *, int, int *); static void change(int, int, int, int); static void sort(struct line *, int); static int newcand(int, int, int); static int search(int *, int, int); static int skipline(int); static int asciifile(FILE *); static int stone(int *, int, int *, int *); static int readhash(FILE *); /* * chrtran points to one of 2 translation tables: cup2low if folding upper to * lower case clow2low if not folding case */ u_char clow2low[256] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff }; u_char cup2low[256] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff }; void diffreg(void) { char buf1[BUFSIZ], buf2[BUFSIZ]; FILE *f1, *f2; int i, j; if (hflag) { diffargv[0] = "diffh"; execv(diffh, diffargv); error("%s", diffh); } chrtran = (iflag ? cup2low : clow2low); if (strcmp(file1, "-") == 0 && strcmp(file2, "-") == 0) errorx("can't specify - -"); if (S_ISDIR(stb1.st_mode)) { file1 = splice(file1, file2); if (stat(file1, &stb1) < 0) error("%s", file1); } else if (!S_ISREG(stb1.st_mode) || strcmp(file1, "-") == 0) { file1 = copytemp(file1, 1); if (stat(file1, &stb1) < 0) error("%s", file1); } if (S_ISDIR(stb2.st_mode)) { file2 = splice(file2, file1); if (stat(file2, &stb2) < 0) error("%s", file2); } else if (!S_ISREG(stb2.st_mode) || strcmp(file2, "-") == 0) { file2 = copytemp(file2, 2); if (stat(file2, &stb2) < 0) error("%s", file2); } if ((f1 = fopen(file1, "r")) == NULL) error("%s", file1); if ((f2 = fopen(file2, "r")) == NULL) error("%s", file2); if (S_ISREG(stb1.st_mode) && S_ISREG(stb2.st_mode) && stb1.st_size != stb2.st_size) goto notsame; for (;;) { i = fread(buf1, 1, BUFSIZ, f1); j = fread(buf2, 1, BUFSIZ, f2); if (i < 0 || j < 0 || i != j) goto notsame; if (i == 0 && j == 0) { fclose(f1); fclose(f2); status = 0; /* files don't differ */ goto same; } for (j = 0; j < i; j++) if (buf1[j] != buf2[j]) goto notsame; } notsame: /* * Files certainly differ at this point; set status accordingly */ status = 1; if (!asciifile(f1) || !asciifile(f2)) { printf("Binary files %s and %s differ\n", file1, file2); exit(status); } prepare(0, f1); prepare(1, f2); fclose(f1); fclose(f2); prune(); sort(sfile[0], slen[0]); sort(sfile[1], slen[1]); member = (int *)file[1]; equiv(sfile[0], slen[0], sfile[1], slen[1], member); member = erealloc(member, (slen[1] + 2) * sizeof(int)); class = (int *)file[0]; unsort(sfile[0], slen[0], class); class = erealloc(class, (slen[0] + 2) * sizeof(int)); klist = emalloc((slen[0] + 2) * sizeof(int)); clist = emalloc(sizeof(cand)); i = stone(class, slen[0], member, klist); free(member); free(class); J = emalloc((len[0] + 2) * sizeof(int)); unravel(klist[i]); free(clist); free(klist); ixold = emalloc((len[0] + 2) * sizeof(long)); ixnew = emalloc((len[1] + 2) * sizeof(long)); check(); output(); status = anychange; same: if (anychange == 0 && (opt == D_CONTEXT || opt == D_UNIFIED)) printf("No differences encountered\n"); } char *tempfiles[2]; char * copytemp(const char *file, int n) { char buf[BUFSIZ], *tempdir, *tempfile; int i, ifd, ofd; if (n != 1 && n != 2) return (NULL); if (strcmp(file, "-") == 0) ifd = STDIN_FILENO; else if ((ifd = open(file, O_RDONLY, 0644)) < 0) error("%s", file); if ((tempdir = getenv("TMPDIR")) == NULL) tempdir = _PATH_TMP; if (asprintf(&tempfile, "%s/diff%d.XXXXXXXX", tempdir, n) == -1) error(NULL); tempfiles[n - 1] = tempfile; signal(SIGHUP, done); signal(SIGINT, done); signal(SIGPIPE, done); signal(SIGTERM, done); ofd = mkstemp(tempfile); if (ofd < 0) error("%s", tempfile); while ((i = read(ifd, buf, BUFSIZ)) > 0) { if (write(ofd, buf, i) != i) error("%s", tempfile); } close(ifd); close(ofd); return (tempfile); } char * splice(char *dir, char *file) { char *tail, *buf; size_t len; if (!strcmp(file, "-")) errorx("can't specify - with other arg directory"); tail = strrchr(file, '/'); if (tail == NULL) tail = file; else tail++; len = strlen(dir) + 1 + strlen(tail) + 1; buf = emalloc(len); snprintf(buf, len, "%s/%s", dir, tail); return (buf); } static void prepare(int i, FILE *fd) { struct line *p; int j, h; fseek(fd, 0L, SEEK_SET); p = emalloc(3 * sizeof(struct line)); for (j = 0; (h = readhash(fd));) { p = erealloc(p, (++j + 3) * sizeof(struct line)); p[j].value = h; } len[i] = j; file[i] = p; } static void prune(void) { int i, j; for (pref = 0; pref < len[0] && pref < len[1] && file[0][pref + 1].value == file[1][pref + 1].value; pref++) ; for (suff = 0; suff < len[0] - pref && suff < len[1] - pref && file[0][len[0] - suff].value == file[1][len[1] - suff].value; suff++) ; for (j = 0; j < 2; j++) { sfile[j] = file[j] + pref; slen[j] = len[j] - pref - suff; for (i = 0; i <= slen[j]; i++) sfile[j][i].serial = i; } } static void equiv(struct line *a, int n, struct line *b, int m, int *c) { int i, j; i = j = 1; while (i <= n && j <= m) { if (a[i].value < b[j].value) a[i++].value = 0; else if (a[i].value == b[j].value) a[i++].value = j; else j++; } while (i <= n) a[i++].value = 0; b[m + 1].value = 0; j = 0; while (++j <= m) { c[j] = -b[j].serial; while (b[j + 1].value == b[j].value) { j++; c[j] = b[j].serial; } } c[j] = -1; } static int stone(int *a, int n, int *b, int *c) { int i, k, y, j, l; int oldc, tc, oldl; k = 0; c[0] = newcand(0, 0, 0); for (i = 1; i <= n; i++) { j = a[i]; if (j == 0) continue; y = -b[j]; oldl = 0; oldc = c[0]; do { if (y <= clist[oldc].y) continue; l = search(c, k, y); if (l != oldl + 1) oldc = c[l - 1]; if (l <= k) { if (clist[c[l]].y <= y) continue; tc = c[l]; c[l] = newcand(i, y, oldc); oldc = tc; oldl = l; } else { c[l] = newcand(i, y, oldc); k++; break; } } while ((y = b[++j]) > 0); } return (k); } static int newcand(int x, int y, int pred) { struct cand *q; clist = erealloc(clist, ++clen * sizeof(cand)); q = clist + clen - 1; q->x = x; q->y = y; q->pred = pred; return (clen - 1); } static int search(int *c, int k, int y) { int i, j, l, t; if (clist[c[k]].y < y) /* quick look for typical case */ return (k + 1); i = 0; j = k + 1; while (1) { l = i + j; if ((l >>= 1) <= i) break; t = clist[c[l]].y; if (t > y) j = l; else if (t < y) i = l; else return (l); } return (l + 1); } static void unravel(int p) { struct cand *q; int i; for (i = 0; i <= len[0]; i++) J[i] = i <= pref ? i : i > len[0] - suff ? i + len[1] - len[0] : 0; for (q = clist + p; q->y != 0; q = clist + q->pred) J[q->x + pref] = q->y + pref; } /* * Check does double duty: * 1. ferret out any fortuitous correspondences due * to confounding by hashing (which result in "jackpot") * 2. collect random access indexes to the two files */ static void check(void) { int i, j, jackpot, c, d; long ctold, ctnew; if ((input[0] = fopen(file1, "r")) == NULL) error("%s", file1); if ((input[1] = fopen(file2, "r")) == NULL) error("%s", file2); j = 1; ixold[0] = ixnew[0] = 0; jackpot = 0; ctold = ctnew = 0; for (i = 1; i <= len[0]; i++) { if (J[i] == 0) { ixold[i] = ctold += skipline(0); continue; } while (j < J[i]) { ixnew[j] = ctnew += skipline(1); j++; } if (bflag || wflag || iflag) { for (;;) { c = getc(input[0]); d = getc(input[1]); ctold++; ctnew++; if (bflag && isspace(c) && isspace(d)) { do { if (c == '\n') break; ctold++; } while (isspace(c = getc(input[0]))); do { if (d == '\n') break; ctnew++; } while (isspace(d = getc(input[1]))); } else if (wflag) { while (isspace(c) && c != '\n') { c = getc(input[0]); ctold++; } while (isspace(d) && d != '\n') { d = getc(input[1]); ctnew++; } } if (chrtran[c] != chrtran[d]) { jackpot++; J[i] = 0; if (c != '\n') ctold += skipline(0); if (d != '\n') ctnew += skipline(1); break; } if (c == '\n') break; } } else { for (;;) { ctold++; ctnew++; if ((c = getc(input[0])) != (d = getc(input[1]))) { /* jackpot++; */ J[i] = 0; if (c != '\n') ctold += skipline(0); if (d != '\n') ctnew += skipline(1); break; } if (c == '\n') break; } } ixold[i] = ctold; ixnew[j] = ctnew; j++; } for (; j <= len[1]; j++) { ixnew[j] = ctnew += skipline(1); } fclose(input[0]); fclose(input[1]); /* * if (jackpot) * fprintf(stderr, "jackpot\n"); */ } /* shellsort CACM #201 */ static void sort(struct line *a, int n) { struct line *ai, *aim, w; int j, m = 0, k; if (n == 0) return; for (j = 1; j <= n; j *= 2) m = 2 * j - 1; for (m /= 2; m != 0; m /= 2) { k = n - m; for (j = 1; j <= k; j++) { for (ai = &a[j]; ai > a; ai -= m) { aim = &ai[m]; if (aim < ai) break; /* wraparound */ if (aim->value > ai[0].value || (aim->value == ai[0].value && aim->serial > ai[0].serial)) break; w.value = ai[0].value; ai[0].value = aim->value; aim->value = w.value; w.serial = ai[0].serial; ai[0].serial = aim->serial; aim->serial = w.serial; } } } } static void unsort(struct line *f, int l, int *b) { int *a, i; a = emalloc((l + 1) * sizeof(int)); for (i = 1; i <= l; i++) a[f[i].serial] = f[i].value; for (i = 1; i <= l; i++) b[i] = a[i]; free(a); } static int skipline(int f) { int i, c; for (i = 1; (c = getc(input[f])) != '\n'; i++) if (c < 0) return (i); return (i); } static void output(void) { int m, i0, i1, j0, j1; input[0] = fopen(file1, "r"); input[1] = fopen(file2, "r"); m = len[0]; J[0] = 0; J[m + 1] = len[1] + 1; if (opt != D_EDIT) { for (i0 = 1; i0 <= m; i0 = i1 + 1) { while (i0 <= m && J[i0] == J[i0 - 1] + 1) i0++; j0 = J[i0 - 1] + 1; i1 = i0 - 1; while (i1 < m && J[i1 + 1] == 0) i1++; j1 = J[i1 + 1] - 1; J[i1] = j1; change(i0, i1, j0, j1); } } else { for (i0 = m; i0 >= 1; i0 = i1 - 1) { while (i0 >= 1 && J[i0] == J[i0 + 1] - 1 && J[i0] != 0) i0--; j0 = J[i0 + 1] - 1; i1 = i0 + 1; while (i1 > 1 && J[i1 - 1] == 0) i1--; j1 = J[i1 - 1] + 1; J[i1] = j1; change(i1, i0, j1, j0); } } if (m == 0) change(1, 0, 1, len[1]); if (opt == D_IFDEF) { for (;;) { #define c i0 c = getc(input[0]); if (c < 0) return; putchar(c); } #undef c } if (anychange != 0) { if (opt == D_CONTEXT) dump_context_vec(); else if (opt == D_UNIFIED) dump_unified_vec(); } } /* * The following struct is used to record change information when * doing a "context" diff. (see routine "change" to understand the * highly mneumonic field names) */ struct context_vec { int a; /* start line in old file */ int b; /* end line in old file */ int c; /* start line in new file */ int d; /* end line in new file */ }; struct context_vec *context_vec_start, *context_vec_end, *context_vec_ptr; #define MAX_CONTEXT 128 /* * indicate that there is a difference between lines a and b of the from file * to get to lines c to d of the to file. If a is greater then b then there * are no lines in the from file involved and this means that there were * lines appended (beginning at b). If c is greater than d then there are * lines missing from the to file. */ static void change(int a, int b, int c, int d) { struct stat stbuf; if (opt != D_IFDEF && a > b && c > d) return; if (anychange == 0) { anychange = 1; if (opt == D_CONTEXT || opt == D_UNIFIED) { stat(file1, &stbuf); printf("%s %s %s", opt == D_CONTEXT ? "***" : "---", file1, ctime(&stbuf.st_mtime)); stat(file2, &stbuf); printf("%s %s %s", opt == D_CONTEXT ? "---" : "+++", file2, ctime(&stbuf.st_mtime)); context_vec_start = emalloc(MAX_CONTEXT * sizeof(struct context_vec)); context_vec_end = context_vec_start + MAX_CONTEXT; context_vec_ptr = context_vec_start - 1; } } if (opt == D_CONTEXT || opt == D_UNIFIED) { /* * If this new change is within 'context' lines of * the previous change, just add it to the change * record. If the record is full or if this * change is more than 'context' lines from the previous * change, dump the record, reset it & add the new change. */ if (context_vec_ptr >= context_vec_end || (context_vec_ptr >= context_vec_start && a > (context_vec_ptr->b + 2 * context) && c > (context_vec_ptr->d + 2 * context))) { if (opt == D_CONTEXT) dump_context_vec(); else dump_unified_vec(); } context_vec_ptr++; context_vec_ptr->a = a; context_vec_ptr->b = b; context_vec_ptr->c = c; context_vec_ptr->d = d; return; } switch (opt) { case D_NORMAL: case D_EDIT: range(a, b, ","); putchar(a > b ? 'a' : c > d ? 'd' : 'c'); if (opt == D_NORMAL) range(c, d, ","); putchar('\n'); break; case D_REVERSE: putchar(a > b ? 'a' : c > d ? 'd' : 'c'); range(a, b, " "); putchar('\n'); break; case D_NREVERSE: if (a > b) printf("a%d %d\n", b, d - c + 1); else { printf("d%d %d\n", a, b - a + 1); if (!(c > d)) /* add changed lines */ printf("a%d %d\n", b, d - c + 1); } break; } if (opt == D_NORMAL || opt == D_IFDEF) { fetch(ixold, a, b, input[0], "< ", 1); if (a <= b && c <= d && opt == D_NORMAL) prints("---\n"); } fetch(ixnew, c, d, input[1], opt == D_NORMAL ? "> " : "", 0); if ((opt == D_EDIT || opt == D_REVERSE) && c <= d) prints(".\n"); if (inifdef) { fprintf(stdout, "#endif /* %s */\n", ifdefname); inifdef = 0; } } static void range(int a, int b, char *separator) { printf("%d", a > b ? b : a); if (a < b) printf("%s%d", separator, b); } static void fetch(long *f, int a, int b, FILE *lb, char *s, int oldfile) { int i, j, c, col, nc; /* * When doing #ifdef's, copy down to current line * if this is the first file, so that stuff makes it to output. */ if (opt == D_IFDEF && oldfile) { long curpos = ftell(lb); /* print through if append (a>b), else to (nb: 0 vs 1 orig) */ nc = f[a > b ? b : a - 1] - curpos; for (i = 0; i < nc; i++) putchar(getc(lb)); } if (a > b) return; if (opt == D_IFDEF) { if (inifdef) { fprintf(stdout, "#else /* %s%s */\n", oldfile == 1 ? "!" : "", ifdefname); } else { if (oldfile) fprintf(stdout, "#ifndef %s\n", ifdefname); else fprintf(stdout, "#ifdef %s\n", ifdefname); } inifdef = 1 + oldfile; } for (i = a; i <= b; i++) { fseek(lb, f[i - 1], SEEK_SET); nc = f[i] - f[i - 1]; if (opt != D_IFDEF) prints(s); col = 0; for (j = 0; j < nc; j++) { c = getc(lb); if (c == '\t' && tflag) do putchar(' '); while (++col & 7); else { putchar(c); col++; } } } } #define POW2 /* define only if HALFLONG is 2**n */ #define HALFLONG 16 #define low(x) (x&((1L<>HALFLONG) /* * hashing has the effect of * arranging line in 7-bit bytes and then * summing 1-s complement in 16-bit hunks */ static int readhash(FILE *f) { unsigned int shift; int t, space; long sum; sum = 1; space = 0; if (!bflag && !wflag) { if (iflag) for (shift = 0; (t = getc(f)) != '\n'; shift += 7) { if (t == -1) return (0); sum += (long)chrtran[t] << (shift #ifdef POW2 &= HALFLONG - 1); #else %= HALFLONG); #endif } else for (shift = 0; (t = getc(f)) != '\n'; shift += 7) { if (t == -1) return (0); sum += (long)t << (shift #ifdef POW2 &= HALFLONG - 1); #else %= HALFLONG); #endif } } else { for (shift = 0;;) { switch (t = getc(f)) { case -1: return (0); case '\t': case ' ': space++; continue; default: if (space && !wflag) { shift += 7; space = 0; } sum += (long)chrtran[t] << (shift #ifdef POW2 &= HALFLONG - 1); #else %= HALFLONG); #endif shift += 7; continue; case '\n': break; } break; } } sum = low(sum) + high(sum); return ((short) low(sum) + (short) high(sum)); } static int asciifile(FILE *f) { char buf[BUFSIZ], *cp; int cnt; if (aflag) return (1); fseek(f, 0L, SEEK_SET); cnt = fread(buf, 1, BUFSIZ, f); cp = buf; while (--cnt >= 0) if (*cp++ & 0200) return (0); return (1); } /* dump accumulated "context" diff changes */ static void dump_context_vec(void) { struct context_vec *cvp = context_vec_start; int lowa, upb, lowc, upd, do_output; int a, b, c, d; char ch; if (context_vec_start > context_vec_ptr) return; b = d = 0; /* gcc */ lowa = max(1, cvp->a - context); upb = min(len[0], context_vec_ptr->b + context); lowc = max(1, cvp->c - context); upd = min(len[1], context_vec_ptr->d + context); printf("***************\n*** "); range(lowa, upb, ","); printf(" ****\n"); /* * output changes to the "old" file. The first loop suppresses * output if there were no changes to the "old" file (we'll see * the "old" lines as context in the "new" list). */ do_output = 0; for (; cvp <= context_vec_ptr; cvp++) if (cvp->a <= cvp->b) { cvp = context_vec_start; do_output++; break; } if (do_output) { while (cvp <= context_vec_ptr) { a = cvp->a; b = cvp->b; c = cvp->c; d = cvp->d; if (a <= b && c <= d) ch = 'c'; else ch = (a <= b) ? 'd' : 'a'; if (ch == 'a') fetch(ixold, lowa, b, input[0], " ", 0); else { fetch(ixold, lowa, a - 1, input[0], " ", 0); fetch(ixold, a, b, input[0], ch == 'c' ? "! " : "- ", 0); } lowa = b + 1; cvp++; } fetch(ixold, b + 1, upb, input[0], " ", 0); } /* output changes to the "new" file */ printf("--- "); range(lowc, upd, ","); printf(" ----\n"); do_output = 0; for (cvp = context_vec_start; cvp <= context_vec_ptr; cvp++) if (cvp->c <= cvp->d) { cvp = context_vec_start; do_output++; break; } if (do_output) { while (cvp <= context_vec_ptr) { a = cvp->a; b = cvp->b; c = cvp->c; d = cvp->d; if (a <= b && c <= d) ch = 'c'; else ch = (a <= b) ? 'd' : 'a'; if (ch == 'd') fetch(ixnew, lowc, d, input[1], " ", 0); else { fetch(ixnew, lowc, c - 1, input[1], " ", 0); fetch(ixnew, c, d, input[1], ch == 'c' ? "! " : "+ ", 0); } lowc = d + 1; cvp++; } fetch(ixnew, d + 1, upd, input[1], " ", 0); } context_vec_ptr = context_vec_start - 1; } /* dump accumulated "unified" diff changes */ static void dump_unified_vec(void) { struct context_vec *cvp = context_vec_start; int lowa, upb, lowc, upd; int a, b, c, d; char ch; if (context_vec_start > context_vec_ptr) return; b = d = 0; /* gcc */ lowa = max(1, cvp->a - context); upb = min(len[0], context_vec_ptr->b + context); lowc = max(1, cvp->c - context); upd = min(len[1], context_vec_ptr->d + context); printf("@@ -%d,%d +%d,%d @@\n", lowa, upb - lowa + 1, lowc, upd - lowc + 1); /* * Output changes in "unified" diff format--the old and new lines * are printed together. */ for (; cvp <= context_vec_ptr; cvp++) { a = cvp->a; b = cvp->b; c = cvp->c; d = cvp->d; /* * c: both new and old changes * d: only changes in the old file * a: only changes in the new file */ if (a <= b && c <= d) ch = 'c'; else ch = (a <= b) ? 'd' : 'a'; switch (ch) { case 'c': fetch(ixold, lowa, a - 1, input[0], " ", 0); fetch(ixold, a, b, input[0], "-", 0); fetch(ixnew, c, d, input[1], "+", 0); break; case 'd': fetch(ixold, lowa, a - 1, input[0], " ", 0); fetch(ixold, a, b, input[0], "-", 0); break; case 'a': fetch(ixnew, lowc, c - 1, input[1], " ", 0); fetch(ixnew, c, d, input[1], "+", 0); break; } lowa = b + 1; lowc = d + 1; } fetch(ixnew, d + 1, upd, input[1], " ", 0); context_vec_ptr = context_vec_start - 1; }