| 1 | #include <stdio.h> |
| 2 | /* |
| 3 | * head - give the first few lines of a stream or of each of a set of files |
| 4 | * |
| 5 | * Bill Joy UCB August 24, 1977 |
| 6 | */ |
| 7 | |
| 8 | int linecnt = 10; |
| 9 | int argc; |
| 10 | |
| 11 | main(Argc, argv) |
| 12 | int Argc; |
| 13 | char *argv[]; |
| 14 | { |
| 15 | register int argc; |
| 16 | char *name; |
| 17 | register char *argp; |
| 18 | static int around; |
| 19 | char obuf[BUFSIZ]; |
| 20 | |
| 21 | setbuf(stdout, obuf); |
| 22 | Argc--, argv++; |
| 23 | argc = Argc; |
| 24 | do { |
| 25 | while (argc > 0 && argv[0][0] == '-') { |
| 26 | linecnt = getnum(argv[0] + 1); |
| 27 | argc--, argv++, Argc--; |
| 28 | } |
| 29 | if (argc == 0 && around) |
| 30 | break; |
| 31 | if (argc > 0) { |
| 32 | close(0); |
| 33 | if (freopen(argv[0], "r", stdin) == NULL) { |
| 34 | perror(argv[0]); |
| 35 | exit(1); |
| 36 | } |
| 37 | name = argv[0]; |
| 38 | argc--, argv++; |
| 39 | } else |
| 40 | name = 0; |
| 41 | if (around) |
| 42 | putchar('\n'); |
| 43 | around++; |
| 44 | if (Argc > 1 && name) |
| 45 | printf("==> %s <==\n", name); |
| 46 | copyout(linecnt); |
| 47 | fflush(stdout); |
| 48 | } while (argc > 0); |
| 49 | } |
| 50 | |
| 51 | copyout(cnt) |
| 52 | register int cnt; |
| 53 | { |
| 54 | register int c; |
| 55 | char lbuf[BUFSIZ]; |
| 56 | |
| 57 | while (cnt > 0 && fgets(lbuf, sizeof lbuf, stdin) != 0) { |
| 58 | printf("%s", lbuf); |
| 59 | fflush(stdout); |
| 60 | cnt--; |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | getnum(cp) |
| 65 | register char *cp; |
| 66 | { |
| 67 | register int i; |
| 68 | |
| 69 | for (i = 0; *cp >= '0' && *cp <= '9'; cp++) |
| 70 | i *= 10, i += *cp - '0'; |
| 71 | if (*cp) { |
| 72 | fprintf(stderr, "Badly formed number\n"); |
| 73 | exit(1); |
| 74 | } |
| 75 | return (i); |
| 76 | } |