Commit | Line | Data |
---|---|---|
9c87fed6 BJ |
1 | static char *sccsid = "@(#)head.c 4.1 (Berkeley) %G%"; |
2 | #include <stdio.h> | |
3 | /* | |
4 | * head - give the first few lines of a stream or of each of a set of files | |
5 | * | |
6 | * Bill Joy UCB August 24, 1977 | |
7 | */ | |
8 | ||
9 | int linecnt = 10; | |
10 | int argc; | |
11 | ||
12 | main(Argc, argv) | |
13 | int Argc; | |
14 | char *argv[]; | |
15 | { | |
16 | register int argc; | |
17 | char *name; | |
18 | register char *argp; | |
19 | static int around; | |
20 | char obuf[BUFSIZ]; | |
21 | ||
22 | setbuf(stdout, obuf); | |
23 | Argc--, argv++; | |
24 | argc = Argc; | |
25 | do { | |
26 | while (argc > 0 && argv[0][0] == '-') { | |
27 | linecnt = getnum(argv[0] + 1); | |
28 | argc--, argv++, Argc--; | |
29 | } | |
30 | if (argc == 0 && around) | |
31 | break; | |
32 | if (argc > 0) { | |
33 | close(0); | |
34 | if (freopen(argv[0], "r", stdin) == NULL) { | |
35 | perror(argv[0]); | |
36 | exit(1); | |
37 | } | |
38 | name = argv[0]; | |
39 | argc--, argv++; | |
40 | } else | |
41 | name = 0; | |
42 | if (around) | |
43 | putchar('\n'); | |
44 | around++; | |
45 | if (Argc > 1 && name) | |
46 | printf("==> %s <==\n", name); | |
47 | copyout(linecnt); | |
48 | fflush(stdout); | |
49 | } while (argc > 0); | |
50 | } | |
51 | ||
52 | copyout(cnt) | |
53 | register int cnt; | |
54 | { | |
55 | register int c; | |
56 | char lbuf[BUFSIZ]; | |
57 | ||
58 | while (cnt > 0 && fgets(lbuf, sizeof lbuf, stdin) != 0) { | |
59 | printf("%s", lbuf); | |
60 | fflush(stdout); | |
61 | cnt--; | |
62 | } | |
63 | } | |
64 | ||
65 | getnum(cp) | |
66 | register char *cp; | |
67 | { | |
68 | register int i; | |
69 | ||
70 | for (i = 0; *cp >= '0' && *cp <= '9'; cp++) | |
71 | i *= 10, i += *cp - '0'; | |
72 | if (*cp) { | |
73 | fprintf(stderr, "Badly formed number\n"); | |
74 | exit(1); | |
75 | } | |
76 | return (i); | |
77 | } |