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- From: mike2@lcuxa.UUCP
- Newsgroups: comp.sources.misc
- Subject: v02i059: Patch for pd-cdiff (MS C, probably others)
- Message-ID: <7242@ncoast.UUCP>
- Date: 18 Feb 88 02:35:18 GMT
- Approved: allbery@ncoast.UUCP
-
- Comp.sources.misc: Volume 2, Issue 59
- Submitted-By: <mike2@lcuxa.UUCP>
- Archive-Name: pd-cdiff-patch
-
- [Nested shars? That's a new one. ++bsa]
-
- Neil Dixon uncovered a flaw in the logic of the cdiff program that
- was distributed early in January, and which was redistributed with
- changes to make it compilable in Turbo C. I've tested his patch
- both on the Unix SysVr2 version and on the PC, and have not found
- any errors. Conversely, the earlier version when compiled in MSC
- 4.0 (but, for some reason, not when compiled in TC 1.5) would
- sporadically come up with "read" errors. Since it now works in MSC as
- well as TC, I've included the appropriate ifdefs for both compilers,
- and have incorporated Neil's patch. (This was for clarity. The line
- numbers in his patch did not correspond precisely to the line numbers
- in the distributed code.) Both the patch as sent to me and the
- revised code are contained below.
-
- As before, I did not write this code. I merely ported it, and of
- course make no warranties whatsoever.
-
- -------------------------CUT HERE-------------------------------
- #!/bin/sh
- echo extracting cdiff.pat ...
- cat >cdiff.pat <<xzyyz
- >From rutgers!mimsy.umd.edu!uunet!mcvax!esatst!neil Wed Feb 3 10:48:40 1988
- Message-Id: <22649.8802021606@esatst.yc.estec.nl>
- To: bellcore!lcuxa!mike2
- Subject: patch for PD context diff.
- Date: Tue, 02 Feb 88 17:06:29 +0100
- From: Neil Dixon <rutgers!mimsy.umd.edu!uunet!mcvax!esatst!neil>
-
- When running the PD context diff program recently submitted to comp.sources.misc
- we get a 'Can't read ...' error, when not performing a context diff. Here's the
- simple patch.
-
- Regards,
- Neil Dixon.
-
-
- Neil Dixon <neil@yc.estec.nl> UUCP: ...!mcvax!esatst!neil,
- Thermal Control & Life Support Division (YCV)
- European Space Research and Technology Centre (ESTEC),
- Noordwijk, The Netherlands.
- Phone: +31 1719 84013
-
-
- #! /bin/sh
- # This is a shell archive, meaning:
- # 1. Remove everything above the #! /bin/sh line.
- # 2. Save the resulting text in a file.
- # 3. Execute the file with /bin/sh (not csh) to create the files:
- # cdiff.patch
- # This archive created: Tue Feb 2 17:05:14 1988
- export PATH; PATH=/bin:$PATH
- if test -f 'cdiff.patch'
- then
- echo shar: will not over-write existing file "'cdiff.patch'"
- else
- cat << \SHAR_EOF > 'cdiff.patch'
- *** cdiff.c
- --- cdiff.c.orig
- **************
- *** 935,942
- }
- }
- putchar('\n');
- ! if ((!eflag && c != 'a') || cflag) {
- ! fetch(oldseek, astart , aend, lenA, infd[0],
- cflag ? (c=='d' ? "- " : "! ") : "< ");
- if (cflag) {
- fputs("--- ", stdout);
- --- 937,944 -----
- }
- }
- putchar('\n');
- ! if (!eflag) {
- ! fetch(oldseek, astart, aend, lenA, infd[0],
- cflag ? (c=='d' ? "- " : "! ") : "< ");
- if (cflag) {
- fputs("--- ", stdout);
- SHAR_EOF
- fi # end of overwriting check
- # End of shell archive
- exit 0
- xzyyz
- echo extracting cdiff2.c ...
- cat >cdiff2.c <<xzyyz
- /* Change the following as appropriate */
- #undef vms
- #undef TURBO /* Note: Use the small model in TC, and
- invoke optimization for speed, registers,
- and jumps. Even so, it still runs slowly! */
- #undef pdp11
- #undef OSK
- #undef DEBUG
- #undef unix
- #define MSC 1 /* Note: The source compiles properly on
- * MSC 4.0 (small model). I have no idea
- * whether it will work on 5.0 */
-
- #ifdef TURBO
- #include <alloc.h>
- #include <errno.h>
- #include <process.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
-
- #else
- #include <stdio.h>
- #include <ctype.h>
- #endif
-
- #ifdef vms
- #include <ssdef.h>
- #include <stsdef.h>
- #define IO_SUCCESS (SS$_NORMAL | STS$M_INHIB_MSG)
- #define IO_ERROR SS$_ABORT
- #endif
- /*
- * Note: IO_SUCCESS and IO_ERROR are defined in the Decus C stdio.h file
- */
- #ifndef IO_SUCCESS
- #define IO_SUCCESS 0
- #endif
- #ifndef IO_ERROR
- #define IO_ERROR 1
- #endif
-
- #define EOS 0
- #ifdef unix
- char temfile[L_tmpnam];
- char *tmpnam();
- #define TEMPFILE (temfile[0]? temfile: (tmpnam(temfile), temfile))
- #else
- #define TEMPFILE "diff.tmp"
- #endif
- #define TRUE 1
- #define FALSE 0
-
- #ifdef pdp11
- #define short int
- #endif
-
- typedef struct candidate {
- int b; /* Line in fileB */
- int a; /* Line in fileA */
- int link; /* Previous candidate */
- } CANDIDATE;
-
- typedef struct line {
- unsigned short hash; /* Hash value etc. */
- short serial; /* Line number */
- } LINE;
-
- LINE *file[2]; /* Hash/line for total file */
- #define fileA file[0]
- #define fileB file[1]
-
- LINE *sfile[2]; /* Hash/line after prefix */
- #define sfileA sfile[0]
- #define sfileB sfile[1]
-
- int len[2]; /* Actual lines in each file */
- #define lenA len[0]
- #define lenB len[1]
-
- int slen[2]; /* Squished lengths */
- #define slenA slen[0]
- #define slenB slen[1]
-
- int prefix; /* Identical lines at start */
- int suffix; /* Identical lenes at end */
-
- FILE *infd[2] = { NULL, NULL }; /* Input file identifiers */
- FILE *tempfd; /* Temp for input redirection */
-
- extern long ftell();
- extern FILE *fopen();
-
- #ifdef TURBO
- extern void *malloc();
- #else
- extern char *malloc();
- #endif
-
- char *fgetss();
- unsigned short hash();
-
- #ifdef AMIGA
- /* Define these types for Amiga C */
- char *savptr;
- int savsiz;
- char *wrk;
- char *wrk2;
- int cpysiz;
- #endif
- /*
- * The following vectors overlay the area defined by fileA
- */
-
- short *class; /* Unsorted line numbers */
- int *klist; /* Index of element in clist */
- CANDIDATE *clist; /* Storage pool for candidates */
- int clength = 0; /* Number of active candidates */
- #define CSIZE_INC 50 /* How many to allocate each time we have to */
- int csize = CSIZE_INC; /* Current size of storage pool */
-
- int *match; /* Longest subsequence */
- long *oldseek; /* Seek position in file A */
-
- /*
- * The following vectors overlay the area defined by fileB
- */
-
- short *member; /* Concatenated equiv. classes */
- long *newseek; /* Seek position in file B */
- char *textb; /* Input from file2 for check */
-
- /*
- * Global variables
- */
-
- int eflag = FALSE; /* Edit script requested */
- int bflag = FALSE; /* Blank supress requested */
- int cflag = FALSE; /* Context printout */
- int iflag = FALSE; /* Ignore case requested */
- char text[257]; /* Input line from file1 */
- extern char *myalloc(); /* Storage allocator */
-
- extern char *compact(); /* Storage compactor */
-
- #ifdef DEBUG
- #ifndef OSK
- #define TIMING
- #endif
- #endif
- #ifdef TIMING
- extern long time();
- extern char *$$mend;
- long totaltime;
- long sectiontime;
- char *mstart;
- #endif
-
- main(argc, argv)
- int argc;
- char **argv;
- /*
- * Diff main program
- */
- {
- register int i;
- register char *ap;
-
- #ifdef OSK
- extern int _memmins;
- _memmins = 16 * 1024; /* tell OSK we will malloc a lot */
- #endif
- #ifdef TIMING
- sectiontime = time(&totaltime);
- #endif
- #ifdef vms
- argc = getredirection(argc,argv);
- #endif
- while (argc > 1 && *(ap = argv[1]) == '-' && *++ap != EOS) {
- while (*ap != EOS) {
- switch ((*ap++)) {
- case 'b':
- bflag++;
- break;
-
- case 'c':
- if (*ap > '0' && *ap <= '9') cflag = *ap++ - '0';
- else cflag = 3;
- break;
-
- case 'e':
- eflag++;
- break;
-
- case 'i':
- iflag++;
- break;
-
- default:
- fprintf(stderr,
- "Warning, bad option '%c'\n",
- ap[-1]);
- break;
- }
- }
- argc--;
- argv++;
- }
-
- if (argc != 3)
- error("Usage: diff [-options] file1 file2");
- if (cflag && eflag) {
- fprintf(stderr,
- "Warning, -c and -e are incompatible, -c supressed.\n");
- cflag = FALSE;
- }
- argv++;
- for (i = 0; i <= 1; i++) {
- if (argv[i][0] == '-' && argv[i][1] == EOS) {
- infd[i] = stdin;
- if ((tempfd = fopen(TEMPFILE, "w")) == NULL)
- cant(TEMPFILE, "work", 1);
- }
- else {
- infd[i] = fopen(argv[i], "r");
- if (!infd[i]) cant(argv[i], "input", 2); /* Fatal error */
- }
- }
-
- if (infd[0] == stdin && infd[1] == stdin)
- error("Can't diff two things both on standard input.");
-
- if (infd[0] == NULL && infd[1] == NULL) {
- cant(argv[0], "input", 0);
- cant(argv[1], "input", 1);
- }
- #ifdef vms
- else if (infd[1] == NULL)
- opendir(1, &argv[1], infd[0]);
- else if (infd[0] == NULL)
- opendir(0, &argv[0], infd[1]);
- #endif
-
- /*
- * Read input, building hash tables.
- */
- input(0);
- input(1);
- squish();
- #ifdef DEBUG
- printf("before sort\n");
- for (i = 1; i <= slenA; i++)
- printf("sfileA[%d] = %6d %06o\n",
- i, sfileA[i].serial, sfileA[i].hash);
- for (i = 1; i <= slenB; i++)
- printf("sfileB[%d] = %6d %06o\n",
- i, sfileB[i].serial, sfileB[i].hash);
- #endif
- sort(sfileA, slenA);
- sort(sfileB, slenB);
- #ifdef TIMING
- ptime("input");
- #endif
- #ifdef DEBUG
- printf("after sort\n");
- for (i = 1; i <= slenA; i++)
- printf("sfileA[%d] = %6d %06o\n",
- i, sfileA[i].serial, sfileB[i].hash);
- for (i = 1; i <= slenB; i++)
- printf("sfileB[%d] = %6d %06o\n",
- i, sfileB[i].serial, sfileB[i].hash);
- #endif
- /*
- * Build equivalence classes.
- */
- member = (short *)fileB;
- equiv();
- member = (short *)compact((char *)member, (slenB + 2) * sizeof (int),
- "squeezing member vector");
- /*
- * Reorder equivalence classes into array class[]
- */
- class = (short *)fileA;
- unsort();
- class = (short *)compact((char *)class, (slenA + 2) * sizeof (int),
- "compacting class vector");
- #ifdef TIMING
- ptime("equiv/unsort");
- #endif
- /*
- * Find longest subsequences
- */
- klist = (int *)myalloc((slenA + 2) * sizeof (int), "klist");
- clist = (CANDIDATE *)myalloc(csize * sizeof (CANDIDATE), "clist");
- i = subseq();
- #ifndef OSK
- free((char *)member);
- free((char *)class);
- #else
- free((char *)member - sizeof(int));
- free((char *)class - sizeof(int));
- #endif
- match = (int *)myalloc((lenA + 2) * sizeof (int), "match");
- unravel(klist[i]);
- #ifndef OSK
- free((char *)clist);
- free((char *)klist);
- #else
- free((char *)clist - sizeof(int));
- free((char *)klist - sizeof(int));
- #endif
- #ifdef TIMING
- ptime("subsequence/unravel");
- #endif
- /*
- * Check for fortuitous matches and output differences
- */
- oldseek = (long *)myalloc((lenA + 2) * sizeof (* oldseek), "oldseek");
- newseek = (long *)myalloc((lenB + 2) * sizeof (* newseek), "newseek");
- textb = myalloc(sizeof text, "textbuffer");
- if (check(argv[0], argv[1]))
- fprintf(stderr, "Spurious match, output is not optimal\n");
- #ifdef TIMING
- ptime("check");
- #endif
- output(argv[0], argv[1]);
- #ifdef TIMING
- ptime("output");
- printf("%ld seconds required\n", sectiontime - totaltime);
- #endif
- if (tempfd != NULL) {
- fclose(tempfd);
- #ifdef unix
- unlink(TEMPFILE);
- #else
- #ifdef OSK
- unlink(TEMPFILE);
- #else
- #ifdef MSC /* MSC 4.0 does not understand disjunctive
- #if's. */
- unlink(TEMPFILE);
- #else
- remove(TEMPFILE);
- #endif
- #endif
- #endif
- }
- }
-
-
- input(which)
- int which; /* 0 or 1 to redefine infd[] */
- /*
- * Read the file, building hash table
- */
- {
- register LINE *lentry;
- register int linect = 0;
- FILE *fd;
- #define LSIZE_INC 200 /* # of line entries to alloc at once */
- int lsize = LSIZE_INC;
-
- lentry = (LINE *)myalloc(sizeof(LINE) * (lsize+3), "line");
- fd = infd[which];
- while (!getline(fd, text)) {
- if (++linect >= lsize) {
- lsize += 200;
- lentry = (LINE *)compact((char *)lentry,
- (lsize + 3) * sizeof(LINE),
- "extending line vector");
- }
- lentry[linect].hash = hash(text);
- }
- /*
- * If input was from stdin ("-" command), finish off the temp file.
- */
- if (fd == stdin) {
- fclose(tempfd);
- tempfd = infd[which] = fopen(TEMPFILE, "r");
- }
- /* If we wanted to be stingy with memory, we could realloc lentry down
- * to its exact size (+3 for some odd reason) here. No need? */
- len[which] = linect;
- file[which] = lentry;
- }
-
- squish()
- /*
- * Look for initial and trailing sequences that have identical hash values.
- * Don't bother building them into the candidate vector.
- */
- {
- register int i;
- register LINE *ap;
- register LINE *bp;
- int j;
- int k;
-
- /*
- * prefix -> first line (from start) that doesn't hash identically
- */
- i = 0; ap = &fileA[1]; bp = &fileB[1];
- while (i < lenA && i < lenB && ap->hash == bp->hash) {
- i++; ap++; bp++;
- }
- prefix = i;
- /*
- * suffix -> first line (from end) that doesn't hash identically
- */
- j = lenA - i;
- k = lenB - i;
- ap = &fileA[lenA];
- bp = &fileB[lenB];
- i = 0;
- while (i < j && i < k && ap->hash == bp->hash) {
- i++; ap--; bp--;
- }
- suffix = i;
- /*
- * Tuck the counts away
- */
- for (k = 0; k <= 1; k++) {
- sfile[k] = file[k] + prefix;
- j = slen[k] = len[k] - prefix - suffix;
-
- for (i = 0, ap = sfile[k]; i <= slen[k]; i++, ap++) {
- ap->serial = i;
- }
- }
- }
-
- sort(vector, vecsize)
- LINE *vector; /* What to sort */
- int vecsize; /* How many to sort */
- /*
- * Sort hash entries
- */
- {
- register int j;
- register LINE *aim;
- register LINE *ai;
- int mid;
- int k;
- LINE work;
-
- for (j = 1; j <= vecsize; j *= 2);
- mid = (j - 1);
- while ((mid /= 2) != 0) {
- k = vecsize - mid;
- for (j = 1; j <= k; j++) {
- for (ai = &vector[j]; ai > vector; ai -= mid) {
- aim = &ai[mid];
- if (aim < ai)
- break; /* ?? Why ?? */
- if (aim->hash > ai->hash ||
- aim->hash == ai->hash &&
- aim->serial > ai->serial)
- break;
- work.hash = ai->hash;
- ai->hash = aim->hash;
- aim->hash = work.hash;
- work.serial = ai->serial;
- ai->serial = aim->serial;
- aim->serial = work.serial;
- }
- }
- }
- }
-
- equiv()
- /*
- * Build equivalence class vector
- */
- {
- register LINE *ap;
- #ifdef TURBO
- union {
- #else
- register union {
- #endif
- LINE *bp;
- short *mp;
- } r;
- register int j;
- LINE *atop;
-
- #ifdef DEBUG
- printf("equiv entry\n");
- for (j = 1; j <= slenA; j++)
- printf("sfileA[%d] = %6d %06o\n",
- j, sfileA[j].serial, sfileA[j].hash);
- for (j = 1; j <= slenB; j++)
- printf("sfileB[%d] = %6d %06o\n",
- j, sfileB[j].serial, sfileB[j].hash);
- #endif
- j = 1;
- ap = &sfileA[1];
- r.bp = &sfileB[1];
- atop = &sfileA[slenA];
- while (ap <= atop && j <= slenB) {
- if (ap->hash < r.bp->hash) {
- ap->hash = 0;
- ap++;
- }
- else if (ap->hash == r.bp->hash) {
- ap->hash = j;
- ap++;
- }
- else {
- r.bp++;
- j++;
- }
- }
- while (ap <= atop) {
- ap->hash = 0;
- ap++;
- }
- sfileB[slenB + 1].hash = 0;
- #ifdef DEBUG
- printf("equiv exit\n");
- for (j = 1; j <= slenA; j++)
- printf("sfileA[%d] = %6d %06o\n",
- j, sfileA[j].serial, sfileA[j].hash);
- for (j = 1; j <= slenB; j++)
- printf("sfileB[%d] = %6d %06o\n",
- j, sfileB[j].serial, sfileB[j].hash);
- #endif
- ap = &sfileB[0];
- atop = &sfileB[slenB];
- r.mp = &member[0];
- while (++ap <= atop) {
- r.mp++;
- *r.mp = -(ap->serial);
- while (ap[1].hash == ap->hash) {
- ap++;
- r.mp++;
- *r.mp = ap->serial;
- }
- }
- r.mp[1] = -1;
- #ifdef DEBUG
- for (j = 0; j <= slenB; j++)
- printf("member[%d] = %d\n", j, member[j]);
- #endif
- }
-
- unsort()
- /*
- * Build class vector
- */
- {
- register int *temp;
- register int *tp;
- #if TURBO
- union {
- #else
- register union {
- #endif
- LINE *ap;
- short *cp;
- } u;
- LINE *evec;
- short *eclass;
- #ifdef DEBUG
- int i;
- #endif
-
- temp = (int *)myalloc((slenA + 1) * sizeof(int), "unsort scratch");
- u.ap = &sfileA[1];
- evec = &sfileA[slenA];
- while (u.ap <= evec) {
- #ifdef DEBUG
- printf("temp[%2d] := %06o\n", u.ap->serial, u.ap->hash);
- #endif
- temp[u.ap->serial] = u.ap->hash;
- u.ap++;
- }
- /*
- * Copy into class vector and free work space
- */
- u.cp = &class[1];
- eclass = &class[slenA];
- tp = &temp[1];
- while (u.cp <= eclass)
- *u.cp++ = *tp++;
- #ifndef OSK
- free((char *) temp);
- #else
- free((char *)temp - sizeof(int));
- #endif
- #ifdef DEBUG
- printf("unsort exit\n");
- for (i = 1; i <= slenA; i++)
- printf("class[%d] = %d %06o\n", i, class[i], class[i]);
- #endif
- }
-
- subseq()
- /*
- * Generate maximum common subsequence chain in clist[]
- */
- {
- int a;
- register unsigned ktop;
- register int b;
- register int s;
- unsigned r;
- int i;
- int cand;
-
- klist[0] = newcand(0, 0, -1);
- klist[1] = newcand(slenA + 1, slenB + 1, -1);
- ktop = 1; /* -> guard entry */
- for (a = 1; a <= slenA; a++) {
- /*
- * For each non-zero element in fileA ...
- */
- if ((i = class[a]) == 0)
- continue;
- cand = klist[0]; /* No candidate now */
- r = 0; /* Current r-candidate */
- do {
- #ifdef DEBUG
- printf("a = %d, i = %d, b = %d\n", a, i, member[i]);
- #endif
- /*
- * Perform the merge algorithm
- */
- if ((b = member[i]) < 0)
- b = -b;
- #ifdef DEBUG
- printf("search(%d, %d, %d) -> %d\n",
- r, ktop, b, search(r, ktop, b));
- #endif
- if ((s = search(r, ktop, b)) != 0) {
- if (clist[klist[s]].b > b) {
- klist[r] = cand;
- r = s;
- cand = newcand(a, b, klist[s-1]);
- #ifdef DEBUG
- dumpklist(ktop, "klist[s-1]->b > b");
- #endif
- }
- if (s >= ktop) {
- klist[ktop + 1] = klist[ktop];
- ktop++;
- #ifdef DEBUG
- klist[r] = cand;
- dumpklist(ktop, "extend");
- #endif
- break;
- }
- }
- } while (member[++i] > 0);
- klist[r] = cand;
- }
- #ifdef DEBUG
- printf("last entry = %d\n", ktop - 1);
- #endif
- return(ktop - 1); /* Last entry found */
- }
-
- int
- newcand(a, b, pred)
- int a; /* Line in fileA */
- int b; /* Line in fileB */
- int pred; /* Link to predecessor, index in cand[] */
- {
- register CANDIDATE *new;
-
- clength++;
- if (++clength >= csize) {
- csize += CSIZE_INC;
- clist = (CANDIDATE *)compact((char *)clist,
- csize * sizeof (CANDIDATE),
- "extending clist");
- }
- new = &clist[clength - 1];
- new->a = a;
- new->b = b;
- new->link = pred;
- return(clength - 1);
- }
-
- search(low, high, b)
- register unsigned low;
- register unsigned high;
- register int b;
- /*
- * Search klist[low..top] (inclusive) for b. If klist[low]->b >= b,
- * return zero. Else return s such that klist[s-1]->b < b and
- * klist[s]->b >= b. Note that the algorithm presupposes the two
- * preset "fence" elements, (0, 0) and (slenA, slenB).
- */
- {
- register int temp;
- register unsigned mid;
-
- if (clist[klist[low]].b >= b)
- return(0);
- while ((mid = (low + high) / 2) > low) {
- if ((temp = clist[klist[mid]].b) > b)
- high = mid;
- else if (temp < b)
- low = mid;
- else {
- return(mid);
- }
- }
- return(mid + 1);
- }
-
-
- unravel(k)
- register int k;
- {
- register int i;
- register CANDIDATE *cp;
- int first_trailer;
- int difference;
-
- first_trailer = lenA - suffix;
- difference = lenB - lenA;
- #ifdef DEBUG
- printf("first trailer = %d, difference = %d\n",
- first_trailer, difference);
- #endif
- for (i = 0; i <= lenA; i++) {
- match[i] = (i <= prefix) ? i
- : (i > first_trailer) ? i + difference
- : 0;
- }
- #ifdef DEBUG
- printf("unravel\n");
- #endif
- while (k != -1) {
- cp = &clist[k];
- #ifdef DEBUG
- if (k < 0 || k >= clength)
- error("Illegal link -> %d", k);
- printf("match[%d] := %d\n", cp->a + prefix, cp->b + prefix);
- #endif
- match[cp->a + prefix] = cp->b + prefix;
- k = cp->link;
- }
- }
-
-
- /*
- * Check for hash matches (jackpots) and collect random access indices to
- * the two files.
- *
- * It should be possible to avoid doing most of the ftell's by noticing
- * that we are not doing a context diff and noticing that if a line
- * compares equal to the other file, we will not ever need to know its
- * file position. FIXME.
- */
- check(fileAname, fileBname)
- char *fileAname;
- char *fileBname;
- {
- register int a; /* Current line in file A */
- register int b; /* Current line in file B */
- int jackpot;
-
- /*
- * The VAX C ftell() returns the address of the CURRENT record, not the
- * next one (as in DECUS C or, effectively, other C's). Hence, the values
- * are "off by one" in the array. OFFSET compensates for this.
- */
- #ifdef vms
- #define OFFSET (-1)
- #else
- #define OFFSET 0
- #endif
-
- b = 1;
- rewind(infd[0]);
- rewind(infd[1]);
- /*
- * See above; these would be over-written on VMS anyway.
- */
- #ifndef vms
- oldseek[0] = ftell(infd[0]);
- newseek[0] = ftell(infd[1]);
- #endif
-
- jackpot = 0;
- #ifdef DEBUG
- printf("match vector\n");
- for (a = 0; a <= lenA; a++)
- printf("match[%d] = %d\n", a, match[a]);
- #endif
- for (a = 1; a <= lenA; a++) {
- if (match[a] == 0) {
- /* Unique line in A */
- oldseek[a+OFFSET] = ftell(infd[0]);
- getline(infd[0], text);
- continue;
- }
- while (b < match[a]) {
- /* Skip over unique lines in B */
- newseek[b+OFFSET] = ftell(infd[1]);
- getline(infd[1], textb);
- b++;
- }
-
- /*
- * Compare the two, supposedly matching, lines.
- * Unless we are going to print these lines, don't bother to
- * remember where they are. We only print matching lines
- * if a context diff is happening, or if a jackpot occurs.
- */
- if (cflag) {
- oldseek[a+OFFSET] = ftell(infd[0]);
- newseek[b+OFFSET] = ftell(infd[1]);
- }
- getline(infd[0], text);
- getline(infd[1], textb);
- if (!streq(text, textb)) {
- fprintf(stderr, "Spurious match:\n");
- fprintf(stderr, "line %d in %s, \"%s\"\n",
- a, fileAname, text);
- fprintf(stderr, "line %d in %s, \"%s\"\n",
- b, fileBname, textb);
- match[a] = 0;
- jackpot++;
- }
-
- b++;
- }
- for (; b <= lenB; b++) {
- newseek[b+OFFSET] = ftell(infd[1]);
- getline(infd[1], textb);
- }
- /*
- * The logical converse to the code up above, for NON-VMS systems, to
- * store away an fseek() pointer at the beginning of the file. For VMS,
- * we need one at EOF...
- */
- #ifdef vms
- oldseek[lenA] = ftell(infd[0]);
- getline(infd[0],text); /* Will hit EOF... */
- newseek[lenB] = ftell(infd[1]);
- getline(infd[1],textb); /* Will hit EOF... */
- #endif
-
- return(jackpot);
- }
-
- output(fileAname, fileBname)
- char *fileAname, *fileBname;
- {
- register int astart;
- register int aend = 0;
- int bstart;
- register int bend;
-
- rewind(infd[0]);
- rewind(infd[1]);
- match[0] = 0;
- match[lenA+1] = lenB + 1;
- if (!eflag) {
- if (cflag) {
- /*
- * Should include ctime style dates after the file names, but
- * this would be non-trivial on OSK. Perhaps there should be
- * a special case for stdin.
- */
- printf("*** %s\n--- %s\n", fileAname, fileBname);
- }
- /*
- * Normal printout
- */
- for (astart = 1; astart <= lenA; astart = aend + 1) {
- /*
- * New subsequence, skip over matching stuff
- */
- while (astart <= lenA
- && match[astart] == (match[astart - 1] + 1))
- astart++;
- /*
- * Found a difference, setup range and print it
- */
- bstart = match[astart - 1] + 1;
- aend = astart - 1;
- while (aend < lenA && match[aend + 1] == 0)
- aend++;
- bend = match[aend + 1] - 1;
- match[aend] = bend;
- change(astart, aend, bstart, bend);
- }
- }
- else {
- /*
- * Edit script output -- differences are output "backwards"
- * for the benefit of a line-oriented editor.
- */
- for (aend = lenA; aend >= 1; aend = astart - 1) {
- while (aend >= 1
- && match[aend] == (match[aend + 1] - 1)
- && match[aend] != 0)
- aend--;
- bend = match[aend + 1] - 1;
- astart = aend + 1;
- while (astart > 1 && match[astart - 1] == 0)
- astart--;
- bstart = match[astart - 1] + 1;
- match[astart] = bstart;
- change(astart, aend, bstart, bend);
- }
- }
- if (lenA == 0)
- change(1, 0, 1, lenB);
- }
-
-
- /*
- * Output a change entry: fileA[astart..aend] changed to fileB[bstart..bend]
- */
- change(astart, aend, bstart, bend)
- int astart;
- int aend;
- int bstart;
- int bend;
- {
- char c;
- /*
- * This catches a "dummy" last entry
- */
- if (astart > aend && bstart > bend)
- return;
- c = (astart > aend) ? 'a' : (bstart > bend) ? 'd' : 'c';
- if (cflag) fputs("**************\n*** ", stdout);
-
- if (c == 'a' && !cflag)
- range(astart-1, astart-1, 0); /* Addition: just print one odd # */
- else
- range(astart, aend, 0); /* Print both, if different */
- if (!cflag) {
- putchar(c);
- if (!eflag) {
- if (c == 'd')
- range(bstart-1, bstart-1, 1); /* Deletion: just print one odd # */
- else
- range(bstart, bend, 1); /* Print both, if different */
- }
- }
- putchar('\n');
- if ((!eflag && c != 'a') || cflag) {
- fetch(oldseek, astart, aend, lenA, infd[0],
- cflag ? (c=='d' ? "- " : "! ") : "< ");
- if (cflag) {
- fputs("--- ", stdout);
- range(bstart, bend, 1);
- fputs(" -----\n", stdout);
- } else if (astart <= aend && bstart <= bend)
- printf("---\n");
- }
- fetch(newseek, bstart, bend, lenB, infd[1],
- cflag ? (c=='a' ? "+ " : "! ") : (eflag ? "" : "> "));
- if (eflag && bstart <= bend)
- printf(".\n");
- }
-
-
- range(from, to, w)
- int from;
- int to;
- int w;
- /*
- * Print a range
- */
- {
- if (cflag) {
- if((from -= cflag) <= 0) from = 1;
- if((to += cflag) > len[w]) to = len[w];
- }
- if (to > from) {
- printf("%d,%d", from, to);
- } else if (to < from) {
- printf("%d,%d", to, from);
- } else {
- printf("%d", from);
- }
- }
-
-
- fetch(seekvec, start, end, trueend, fd, pfx)
- long *seekvec;
- register int start;
- register int end;
- int trueend;
- FILE *fd;
- char *pfx;
- /*
- * Print the appropriate text
- */
- {
- register int i;
- register int first;
- register int last;
-
- if (cflag) {
- if((first = start - cflag) <= 0) first = 1;
- if((last = end + cflag) > trueend) last = trueend;
- } else {
- first = start;
- last = end;
- }
- if (fseek(fd, seekvec[first], 0) != 0) {
- printf("?Can't read line %d at %08lx (hex) in file%c\n",
- start, seekvec[first],
- (fd == infd[0]) ? 'A' : 'B');
- }
- else {
- for (i = first; i <= last; i++) {
- if (fgetss(text, sizeof text, fd) == NULL) {
- printf("** Unexpected end of file\n");
- break;
- }
- #ifdef DEBUG
- printf("%5d: %s%s\n", i, pfx, text);
- #else
- fputs((cflag && (i<start || i>end)) ? " " : pfx, stdout);
- fputs(text, stdout);
- putchar('\n');
- #endif
- }
- }
- }
-
-
- /*
- * Input routine, read one line to buffer[], return TRUE on eof, else FALSE.
- * The terminating newline is always removed. If "-b" was given, trailing
- * whitespace (blanks and tabs) are removed and strings of blanks and
- * tabs are replaced by a single blank. Getline() does all hacking for
- * redirected input files.
- */
- int
- getline(fd, buffer)
- FILE *fd;
- char *buffer;
- {
- register char *top;
- register char *fromp;
- register char c;
-
- if (fgetss(buffer, sizeof text, fd) == NULL) {
- *buffer = EOS;
- return(TRUE);
- }
- if (fd == stdin)
- fputss(buffer, tempfd);
- if (bflag || iflag) {
- top = buffer;
- fromp = buffer;
- while ((c = *fromp++) != EOS) {
- if (bflag && (c == ' ' || c == '\t')) {
- c = ' ';
- while (*fromp == ' ' || *fromp == '\t')
- fromp++;
- }
- if (iflag)
- c = tolower(c);
- *top++ = c;
- }
- if (bflag && top[-1] == ' ')
- top--;
- *top = EOS;
- }
- return(FALSE);
- }
- static unsigned short crc16a[] = {
- 0000000, 0140301, 0140601, 0000500,
- 0141401, 0001700, 0001200, 0141101,
- 0143001, 0003300, 0003600, 0143501,
- 0002400, 0142701, 0142201, 0002100,
- };
- static unsigned short crc16b[] = {
- 0000000, 0146001, 0154001, 0012000,
- 0170001, 0036000, 0024000, 0162001,
- 0120001, 0066000, 0074000, 0132001,
- 0050000, 0116001, 0104001, 0043000,
- };
-
- unsigned short
- hash(buffer)
- char *buffer;
- /*
- * Return the CRC16 hash code for the buffer
- * Algorithm from Stu Wecker (Digital memo 130-959-002-00).
- */
- {
- register unsigned short crc;
- register char *tp;
- register short temp;
-
- crc = 0;
- for (tp = buffer; *tp != EOS;) {
- temp = *tp++ ^ crc; /* XOR crc with new char */
- crc = (crc >> 8)
- ^ crc16a[(temp & 0017)]
- ^ crc16b[(temp & 0360) >> 4];
- }
- #ifdef DEBUG_ALL
- printf("%06o: %s\n", (crc == 0) ? 1 : crc, buffer);
- #endif
- return((crc == 0) ? (unsigned short) 1 : crc);
- }
-
-
- #ifdef vms
- opendir(which, arg, okfd)
- int which; /* Which file to open (0 or 1) */
- char **arg; /* File name argument, &argv[which] */
- FILE *okfd; /* File name (already open) */
- {
- register char *tp;
- register int c;
- register char *newname;
-
- fgetname(okfd, text);
- /*
- * Skip over device name
- */
- for (tp = text; (c = *tp) && c != ':'; tp++);
- if (c) tp++;
- else tp = text;
- /*
- * Skip over [UIC] or [PPN] if present
- */
- if (*tp == '[' || *tp == '(') {
- while ((c = *tp++) && c != ']' && c != ')');
- if (c == 0) {
- fprintf(stderr, "?Bug: bad file name \"%s\"\n",
- text);
- tp--;
- }
- }
- strcpy(text, tp);
- /*
- * Don't include version
- */
- for (tp = text; (c = *tp) && c != ';'; tp++);
- *tp = 0;
- /*
- * Now, text has the file name, tp - text, its length,
- * and *arg the (possible) directory name. Create a new
- * file name for opening.
- */
- #ifndef OSK
- if ((newname = malloc(tp - text + strlen(*arg) + 1)) == NULL)
- error("Out of space at start");
- #ifdef AMIGA
- savsiz = tp - text + strlen(*arg) + 1;
- savptr = newname;
- #endif
- #else
- newname = myalloc(tp - text + strlen(*arg) + 1, "Out of space at start");
- #endif
- concat(newname, *arg, text, NULL);
- if ((infd[which] = fopen(newname, "r")) == NULL)
- cant(*arg, "constructed input", 1);
- else
- *arg = newname;
- }
- /* Amiga C doesn't have all these extensions for directory... */
- #endif
-
- char *
- myalloc(amount, why)
- int amount;
- char *why;
- /*
- * Allocate or crash.
- */
- {
- register char *pointer;
-
- #ifdef OSK
- amount += sizeof(int);
- #endif
- if ((pointer = malloc((unsigned) amount)) == NULL)
- noroom(why);
- #ifdef OSK
- *((int *)pointer) = amount;
- pointer += sizeof(int);
- #ifdef DEBUG
- fprintf(stderr, "Myalloc: %d at %06o\n", amount, pointer);
- #endif
- #endif
- #ifdef AMIGA
- savsiz = amount;
- savptr = pointer;
- #endif
-
- return (pointer);
- }
-
-
- /*
- * Reallocate pointer, compacting storage
- *
- * The "compacting storage" part is probably not relevant any more.
- * There used to be horrid code here that malloc'd one byte and freed
- * it at magic times, to cause garbage collection of the freespace
- * or something. It's safely gone now, you didn't have to see it.
- * -- John Gilmore, Nebula Consultants, Sept 26, 1986
- */
- char *
- compact(pointer, new_amount, why)
- char *pointer;
- int new_amount;
- char *why;
- {
- register char *new_pointer;
-
- #ifndef AMIGA
- #ifndef OSK
- #ifdef TURBO
- extern void *realloc();
- #else
- extern char *realloc();
- #endif
-
- if ((new_pointer = realloc(pointer, (unsigned) new_amount)) == NULL){
- noroom(why);
- }
- #else
- register int old_amount;
- new_amount += sizeof(int);
- if((new_pointer = malloc(new_amount)) == NULL) noroom(why);
- *(int *)new_pointer = new_amount;
- new_pointer += sizeof(int);
- old_amount = *(((int *)pointer)-1);
- /* _strass is like bcopy with the first two arguments reversted */
- _strass(new_pointer, pointer, (new_amount <= old_amount ?
- new_amount : old_amount) - sizeof(int));
- #ifdef DEBUG
- fprintf(stderr, "compact %d to %d from %06o to %06o\n",
- old_amount, new_amount, pointer, new_pointer);
- #endif
- free(pointer - sizeof(int));
- #endif
- #else
- /*
- * This routine is heavily dependent on C storage allocator hacks
- * For Amiga, we can't rely on storage being left alone "up to"
- * the boundary of allocation as in VMS or RSX. Therefore we have
- * to be different here and allocate a new larger segment, then
- * free the old one. Messy but hopefully it will work.
- */
- extern char *malloc();
-
- /* No realloc(). Do a malloc and copy it. */
- if ((new_pointer = malloc((unsigned) new_amount)) == NULL){
- noroom(why);
- }
- /* This MUST assume the program calls compact using the old pointer as the
- last call of malloc... Reason is that RSX version is really simpleminded */
- cpysiz=savsiz;
- /* Complain if deallocate area not same as last allocate area */
- if (savptr != pointer) bogus(why);
- wrk2=new_pointer;
- for (wrk=pointer;cpysiz > 0;cpysiz--){
- /* copy data to new area */
- *wrk2++ = *wrk++;
- }
- /* when done, free old memory area. */
- free(pointer);
- #endif
-
- #ifndef OSK
- #ifdef DEBUG
- if (new_pointer != pointer) {
- fprintf(stderr, "moved from %06o to %06o\n",
- pointer, new_pointer);
- }
- /* rdump(new_pointer, why);
- */
- #endif
- #endif
- return (new_pointer);
- }
-
- noroom(why)
- char *why;
- {
- fprintf(stderr, "?DIFF-F-out of room when %s\n", why);
- exit(IO_ERROR);
- }
-
- #ifdef AMIGA
- bogus(why)
- char *why;
- {
- fprintf(stderr, "?DIFF-F-invalid compaction when %s\n", why);
- exit(IO_ERROR);
- }
- #endif
-
- #ifdef DEBUG
- rdump(pointer, why)
- int *pointer;
- char *why;
- /*
- * Dump memory block
- */
- {
- int *last;
- int count;
-
- last = ((int **)pointer)[-1];
- fprintf(stderr, "dump %s of %06o -> %06o, %d words",
- why, pointer, last, last - pointer);
- last = (int *)(((int) last) & ~1);
- for (count = 0; pointer < last; ++count) {
- if ((count & 07) == 0) {
- fprintf(stderr, "\n%06o", pointer);
- }
- fprintf(stderr, "\t%06o", *pointer);
- pointer++;
- }
- fprintf(stderr, "\n");
- }
- #endif
- cant(filename, what, fatalflag)
- char *filename;
- char *what;
- int fatalflag;
- /*
- * Can't open file message
- */
- {
- fprintf(stderr, "Can't open %s file \"%s\": ", what, filename);
- #ifndef OSK
- perror((char *)NULL);
- #else
- prerr(0, errno);
- #endif
- if (fatalflag) {
- exit(fatalflag);
- }
- }
- #ifdef DEBUG
- dump(d_linep, d_len, d_which)
- LINE *d_linep;
- {
- register int i;
-
- printf("Dump of file%c, %d elements\n", "AB"[d_which], d_len);
- printf("linep @ %06o\n", d_linep);
- for (i = 0; i <= d_len; i++) {
- printf("%3d %6d %06o\n", i,
- d_linep[i].serial, d_linep[i].hash);
- }
- }
-
- dumpklist(kmax, why)
- int kmax;
- char *why;
- /*
- * Dump klist
- */
- {
- register int i;
- register CANDIDATE *cp;
- register int count;
-
- printf("\nklist[0..%d] %s, clength = %d\n", kmax, why, clength);
- for (i = 0; i <= kmax; i++) {
- cp = &clist[klist[i]];
- printf("%2d %2d", i, klist[i]);
- if (cp >= &clist[0] && cp < &clist[clength])
- printf(" (%2d %2d -> %2d)\n", cp->a, cp->b, cp->link);
- else if (klist[i] == -1)
- printf(" End of chain\n");
- else printf(" illegal klist element\n");
- }
- for (i = 0; i <= kmax; i++) {
- count = -1;
- for (cp = (CANDIDATE *)klist[i]; cp > &clist[0];
- cp = (CANDIDATE *)&cp->link) {
- if (++count >= 6) {
- printf("\n ");
- count = 0;
- }
- printf(" (%2d: %2d,%2d -> %d)",
- cp-clist, cp->a, cp->b, cp->link);
- }
- printf("\n");
- }
- printf("*\n");
- }
- #endif
- #ifdef TIMING
- ptime(why)
- char *why;
- /*
- * Dump time buffer
- */
- {
- long ttemp;
-
- ttemp = time(NULL);
- printf("%ld seconds for %s\n",
- ttemp - sectiontime, why);
- sectiontime = ttemp;
- }
- #endif
-
- /*
- * s t r e q . c
- */
-
- /*)LIBRARY
- */
-
-
- /* #define EOS 0
- #define FALSE 0
- #define TRUE 1
- */
- int
- streq(s1, s2)
- register char *s1;
- register char *s2;
- /*
- * TRUE if strings are identical
- */
- {
- while (*s1++ == *s2) {
- if (*s2++ == EOS)
- return (TRUE);
- }
- return (FALSE);
- }
- /*
- * e r r o r . c
- */
-
- /*)LIBRARY
- */
-
-
- /* VARARGS */
- error(format, args)
- char *format;
- /*
- * Error message before retiring.
- */
- {
- fprintf(stderr, format, &args);
- putc('\n', stderr);
- _error();
- }
-
- _error()
- {
- exit(1);
- }
-
- /* #include <stdio.h> */
-
- fputss(s, iop)
- register char *s;
- register FILE *iop;
- /*
- * Like fput() except that it puts a newline at the end of the line.
- */
- {
- #ifndef OSK
- /*
- * Why wasn't this written like the OSK section? What's the difference between
- * fputc and putc other than I've never heard of fputc?
- */
- register c;
-
- while (c = *s++)
- fputc(c, iop);
- fputc('\n', iop);
- #else
- fputs(s, iop);
- putc('\n', iop);
- #endif
- }
-
-
- /*
- * Fgetss() is like fgets() except that the terminating newline
- * is removed.
- */
- char *fgetss(s, n, iop)
- char *s;
- register FILE *iop;
- {
- register c;
- register char *cs;
-
- cs = s;
- /*
- * The getc in the next line used to be an "fgetc". Change it back if
- * getc doesn't work on your system, though that would be odd.
- */
- while ((c = getc(iop))>=0 && --n>0) {
- if (c=='\n')
- break;
- *cs++ = c;
- }
- if (c<0 && cs==s)
- return((char *)NULL);
- *cs = '\0'; /* Overwrite newline as null */
- return(s);
- }
- xzyyz
- echo done
- ---
- Mike Slomin
- bellcore!lcuxa!mike2
-