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| author | Jeffrey Armstrong <jeffrey.armstrong@approximatrix.com> | 2014-01-06 20:44:03 -0500 |
|---|---|---|
| committer | Jeffrey Armstrong <jeffrey.armstrong@approximatrix.com> | 2014-01-06 20:44:03 -0500 |
| commit | ab5153e97557791e2c12418ad3f53f53bed2a67a (patch) | |
| tree | d4fec73b911307c743416b45bade86db8c75bbb3 /fcomp.c | |
| parent | 59a9b205dfb6d68545e75f28083cf68eb064547d (diff) | |
| download | prism-ab5153e97557791e2c12418ad3f53f53bed2a67a.tar.gz prism-ab5153e97557791e2c12418ad3f53f53bed2a67a.zip | |
Prism now supports diff versus the repository
Diffstat (limited to 'fcomp.c')
| -rw-r--r-- | fcomp.c | 240 |
1 files changed, 240 insertions, 0 deletions
@@ -0,0 +1,240 @@ +/* fcomp.c:
+
+ This code has been adapted from:
+
+ Software Practice and Experience
+ Vol 15, pp. 1025-1040, November 1985.
+
+ "A File Comparison Program"
+ by Miller and Myers
+ http://tx0.org/7eq
+
+ The modifications basically allow calling the diff routine
+ from a separate program, upping the max lines, and modernizing
+ some portions of the code. Please don't ask me about the
+ theory involved, I do not understand it.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "prism.h"
+
+#define MAXLINES 15000
+#define ORIGIN MAXLINES
+#define INSERT 1
+#define DELETE 2
+
+struct edit {
+ struct edit *link;
+ int op;
+ int line1;
+ int line2;
+};
+
+static char **A, **B;
+
+static void fatal(const char *msg)
+{
+ printf(" ERR: %s\n",msg);
+}
+
+static void exceed(int d)
+{
+ printf(" ERR: the files differ in at least %d lines\n",d);
+}
+
+static int in_file(const char *filename, char **P)
+{
+char *buf, *save;
+FILE *fp, *fopen();
+int lines = 0;
+
+ if ((fp = fopen(filename,"r")) == NULL)
+ {
+ fatal("cannot open file");
+ return PRET_READERROR;
+ }
+
+ buf = (char *)malloc(256*sizeof(char));
+ if(buf == NULL)
+ return PRET_ERROR;
+
+ while(fgets(buf,100,fp) != NULL)
+ {
+ if (lines >= MAXLINES) {
+ fatal("file is to large for diff");
+ return PRET_ERROR;
+ }
+
+ save = (char *)malloc((strlen(buf)+1)*sizeof(char));
+ if (save == NULL) {
+ fatal("not enough room to save the files");
+ return PRET_ERROR;
+ }
+
+ P[lines++] = save;
+ strcpy(save, buf);
+ }
+ fclose(fp);
+
+ free(buf);
+ return(lines);
+}
+
+static void put_scr(struct edit *start, const char *fname1, const char *fname2)
+{
+ struct edit *ep, *behind, *ahead, *a, *b;
+ int change;
+
+ ahead = start;
+ ep = NULL;
+ while (ahead != NULL)
+ {
+ behind = ep;
+ ep = ahead;
+ ahead = ahead->link;
+ ep->link = behind;
+ }
+
+ while( ep != NULL && 0 == 0)
+ {
+ b = ep;
+ if (ep->op == INSERT)
+ //printf("Inserted after line %d:\n",ep->line1);
+ printf("line %s:%d || %s:%d\n", fname1, ep->line1, fname2, ep->line2);
+ else
+ {
+ do
+ {
+ a = b;
+ b = b->link;
+ } while (b!=NULL && b->op == DELETE && b->line1 == a->line1+1);
+
+ change = (b!=NULL && b->op == INSERT && b->line1 == a->line1);
+
+ if (a == ep)
+ printf("line %s:%d || %s:%d\n", fname1, ep->line1, fname2, ep->line2);
+ //printf("line %d:\n",ep->line1);
+ else
+ printf("line %s:%d-%d || %s:%d-%d\n", fname1, ep->line1, a->line1, fname2, ep->line2, a->line2);
+ //printf("lines %d-%d:\n",ep->line1,a->line1);
+
+ do
+ {
+ printf("-%s",A[ep->line1-1]);
+ ep = ep->link;
+ } while (ep != b);
+
+ if (!change) {
+ printf("\n");
+ continue;
+ }
+ }
+ do
+ {
+ printf("+%s",B[ep->line2-1]);
+ ep = ep->link;
+ } while (ep != NULL && ep->op == INSERT && ep->line1 == b->line1);
+
+ printf("\n");
+ }
+}
+
+
+int compare_files(const char *fname1, const char *fname2)
+{
+ int max_d,
+ m,
+ n,
+ lower,
+ upper,
+ d,
+ k,
+ row,
+ col;
+
+ int *last_d;
+ struct edit **script;
+
+ struct edit *new;
+
+ last_d = (int *)malloc((2*MAXLINES+1)*sizeof(int));
+ script = (struct edit **)malloc((2*MAXLINES+1)*sizeof(struct edit *));
+
+ A = (char **)malloc(MAXLINES*sizeof(char *));
+ B = (char **)malloc(MAXLINES*sizeof(char *));
+ if(A == NULL || B == NULL) return PRET_ERROR;
+ memset(A, 0, MAXLINES);
+ memset(B, 0, MAXLINES);
+
+ max_d = 2*MAXLINES;
+
+ m = in_file(fname1,A);
+ n = in_file(fname2,B);
+
+ for (row=0 ; row<m && row < n && strcmp(A[row],B[row]) == 0 ; ++row)
+ ;
+ last_d[ORIGIN] = row;
+ script[ORIGIN] = NULL;
+ lower = (row == m) ? ORIGIN + 1 : ORIGIN - 1;
+ upper = (row == n) ? ORIGIN - 1 : ORIGIN + 1;
+ if (lower > upper)
+ {
+ printf(" the files are identical\n");
+ return PRET_OK;
+ }
+
+ for (d = 1 ; d <= max_d ; ++d)
+ {
+ for ( k = lower ; k <= upper ; k +=2)
+ {
+ new = (struct edit *) malloc(sizeof(struct edit));
+ if (new == NULL) {
+ exceed(d);
+ return PRET_ERROR;
+ }
+
+ if (k == ORIGIN-d || k != ORIGIN+d && last_d[k+1] >= last_d[k-1])
+ {
+ row = last_d[k+1]+1;
+ new->link = script[k+1];
+ new->op = DELETE;
+ }
+ else
+ {
+ row = last_d[k-1];
+ new->link = script[k-1];
+ new->op = INSERT;
+ }
+ new->line1 = row;
+ new->line2 = col = row + k - ORIGIN;
+ script[k] = new;
+
+ while(row < m && col < n && strcmp(A[row],B[col]) == 0)
+ {
+ ++row;
+ ++col;
+ }
+ last_d[k] = row;
+
+ if (row == m && col == n)
+ {
+ put_scr(script[k], fname1, fname2);
+ return PRET_OK;
+ }
+ if (row == m)
+ lower = k+2;
+
+ if (col == n)
+ upper = k-2;
+ }
+ --lower;
+ ++upper;
+ }
+
+ exceed(d);
+ return PRET_ERROR;
+}
+
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