Commit | Line | Data |
---|---|---|
9469ab1e BJ |
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 | } |