/* whatsnew - mark changes in a patched file Author: Andy Tanenbaum */ /* MINIX programs are constantly being updated. When a cdiff patch comes in, * it would be nice to be able to apply the patch, and then list the new file, * which the changed lines marked somehow. This program allows that. Suppose * prog.c is the newly patched file and prog.cdif is the cdiff listing that was * used to produce it. Then the command * * whatsnew prog.c prog.cdif * * will copy prog.c to standard output, marking all added or changed lines * with + or ! at the end, respectively. Output lines are forced to a standard * length to make the + and ! symbols easy to find. The default length is 80, * but it can be changed using a flag. For example, * * whatsnew -75 prog.c prog.cdif * * which pads or truncates the output lines to 75 characters before appending * ! or +. Tabs are converted to spaces in the process. */ #include #include #include #define MAX_WIDTH 256 /* max line length */ #define HEAP_LINES 10000 /* max length of the diff listing */ #define HEAP_BYTES 30000 /* total space for saved lines */ #define HASH_SIZE 10 /* how much of a line is the hash key */ #define TAB_WIDTH 8 /* how far apart are the tab stops */ #define DEF_WIDTH 80 /* default width */ int cdif_found = 0; /* set to 1 if cdif entry found */ char *indices[HEAP_LINES]; /* pointers into the heap */ char heap[HEAP_BYTES]; /* the + and ! lines are saved here. */ int lines_used; /* number of index slots used */ char *hp = heap; /* pointer to end of the heap */ int width = DEF_WIDTH; /* how wide to print the listing */ _PROTOTYPE(int main, (int argc, char **argv)); _PROTOTYPE(void eat_cdif, (FILE *cdif, char *name)); _PROTOTYPE(void read_and_print, (FILE *newf)); _PROTOTYPE(int present, (char *line, char *name)); _PROTOTYPE(void enter_line, (char *line)); _PROTOTYPE(int hash, (char *p)); _PROTOTYPE(void print_line, (char *line, int c)); _PROTOTYPE(void usage, (void)); int main(argc, argv) int argc; char *argv[]; { int k; char *p; FILE *newf, *cdif; /* Process the command line. */ if (argc < 2) usage(); k = 1; p = argv[1]; if (*p == '-') { width = atoi(p + 1); if (width < 0 || width > MAX_WIDTH) { fprintf(stderr, "%s: max line size is %d\n",argv[0],MAX_WIDTH); exit(1); } k++; if (argc != 4) usage(); } else { if (argc != 3) usage(); } newf = fopen(argv[k], "r"); if (newf == NULL) { fprintf(stderr, "%s: cannot open %s\n", argv[0], argv[k]); exit(1); } cdif = fopen(argv[k + 1], "r"); if (cdif == NULL) { fprintf(stderr, "%s: cannot open %s\n", argv[0], argv[k + 1]); exit(1); } /* Read the cdif file and hash all the relevant lines. */ eat_cdif(cdif, argv[k]); /* Read and print the new file. */ read_and_print(newf); return(0); } void eat_cdif(cdif, name) FILE *cdif; char *name; { char line[MAX_WIDTH]; /* First find the start of the relevant cdif stuff. */ while (fgets(line, MAX_WIDTH, cdif) != NULL) { if (strncmp(line, "*** ", (size_t)4) != 0) continue; if (present(line, name) && present(line, ":")) { cdif_found = 1; break; } } if (cdif_found == 0) { fprintf(stderr, "no cdif found for %s\n", name); exit(2); } /* We found it. Save all the ! and + lines in the hash table. */ while (fgets(line, MAX_WIDTH, cdif) != NULL) { if (strncmp(line, "*** ", (size_t)4) == 0 && present(line, ":")) break; if (line[0] != '+' && line[0] != '!') continue; if (line[1] != ' ') continue; enter_line(line); } } void read_and_print(newf) FILE *newf; { int h, hit; char line[MAX_WIDTH], c; /* Examine each line in the patched file. */ while (fgets(line, MAX_WIDTH, newf) != NULL) { /* Hash the line and see if it is in the table. */ hit = -1; h = hash(line); while (indices[h] != 0) { if (strcmp(line, indices[h] + 2) == 0) { hit = h; break; } h = (h + 1) % HEAP_LINES; } c = (hit >= 0 ? *(indices[h]) : ' '); print_line(line, c); } } int present(line, name) char *line, *name; { /* Scan line to see if the string name is present in it anywhere. If so, * return 1, else return 0. */ register int n; register char *p; p = line; n = strlen(name); while (*p != 0) { if (strncmp(p, name, (size_t)n) == 0) return(1); p++; } return(0); } void enter_line(line) char *line; { /* Enter a line in the hash table. Note that the first two characters * do not count, as they have been added by cdiff. */ int n, h; /* Certain lines should not be entered as they occur often. */ n = strlen(line) - 2; if (n == 1) return; /* don't enter null lines */ if (strncmp(line, "+ /*==", (size_t)6) == 0) return; if (strncmp(line, "+ *==", (size_t)6) == 0) return; if (strncmp(line, "+ {", (size_t)5) == 0) return; if (strncmp(line, "+ }", (size_t)5) == 0) return; if (strncmp(line, "+ {", (size_t)3) == 0) return; if (strncmp(line, "+ }", (size_t)3) == 0) return; if (strncmp(line, "+ \t{", (size_t)4) == 0) return; if (strncmp(line, "+ \t}", (size_t)4) == 0) return; if (strncmp(line, "+ else", (size_t)6) == 0) return; if (strncmp(line, "+ #end", (size_t)6) == 0) return; if (lines_used == HEAP_LINES) { fprintf(stderr, "cdif listing has too many lines\n"); exit(1); } if (hp + n >= &heap[HEAP_BYTES]) { fprintf(stderr, "cdif listing has too many bytes\n"); exit(1); } /* Make the heap entry. */ h = hash(line + 2); while (indices[h] != 0) h = (h + 1) % HEAP_LINES; indices[h] = hp; /* indices table points to the lines */ strcpy(hp, line); /* first two chars also copied */ lines_used++; /* count # table slots used */ hp += n + 3; /* 0 byte counts also */ } int hash(p) char *p; { /* Compute and return the hash code of p. */ int i, n; unsigned h; n = strlen(p); if (n > HASH_SIZE) n = HASH_SIZE; h = 0; for (i = 0; i < n; i++) { h += 23 * i * (int) *p; p++; } h = h % HEAP_LINES; return((int) h); } void print_line(line, c) char *line, c; { /* Print the line. */ int col, spaces; char out_buf[3 * MAX_WIDTH], *p, *q; p = line; q = out_buf; col = 0; while (*p != '\n') { /* This loop executed once for each character in the line. */ if (*p != '\t') { /* Not a tab. */ *q++ = *p++; col++; } else { /* Tab. */ spaces = TAB_WIDTH - (col % TAB_WIDTH); col += spaces; while (spaces--) *q++ = ' '; p++; } } while (q < &out_buf[width]) *q++ = ' '; q = &out_buf[width]; *q++ = ' '; *q++ = c; *q++ = '\n'; *q = 0; fputs(out_buf, stdout); } void usage() { fprintf(stderr, "Usage: whatsnew [-] file file.cdif\n"); exit(1); }
