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22e155fc DF |
1 | /* |
2 | * Copyright (c) 1980 Regents of the University of California. | |
3 | * All rights reserved. The Berkeley software License Agreement | |
4 | * specifies the terms and conditions for redistribution. | |
5 | */ | |
6 | ||
7 | #ifndef lint | |
8 | char copyright[] = | |
9 | "@(#) Copyright (c) 1980 Regents of the University of California.\n\ | |
10 | All rights reserved.\n"; | |
11 | #endif not lint | |
12 | ||
13 | #ifndef lint | |
14 | static char sccsid[] = "@(#)head.c 5.1 (Berkeley) %G%"; | |
15 | #endif not lint | |
16 | ||
9c87fed6 BJ |
17 | #include <stdio.h> |
18 | /* | |
19 | * head - give the first few lines of a stream or of each of a set of files | |
20 | * | |
21 | * Bill Joy UCB August 24, 1977 | |
22 | */ | |
23 | ||
24 | int linecnt = 10; | |
25 | int argc; | |
26 | ||
27 | main(Argc, argv) | |
28 | int Argc; | |
29 | char *argv[]; | |
30 | { | |
31 | register int argc; | |
32 | char *name; | |
33 | register char *argp; | |
34 | static int around; | |
9c87fed6 | 35 | |
9c87fed6 BJ |
36 | Argc--, argv++; |
37 | argc = Argc; | |
38 | do { | |
39 | while (argc > 0 && argv[0][0] == '-') { | |
40 | linecnt = getnum(argv[0] + 1); | |
41 | argc--, argv++, Argc--; | |
42 | } | |
43 | if (argc == 0 && around) | |
44 | break; | |
45 | if (argc > 0) { | |
46 | close(0); | |
47 | if (freopen(argv[0], "r", stdin) == NULL) { | |
48 | perror(argv[0]); | |
49 | exit(1); | |
50 | } | |
51 | name = argv[0]; | |
52 | argc--, argv++; | |
53 | } else | |
54 | name = 0; | |
55 | if (around) | |
56 | putchar('\n'); | |
57 | around++; | |
58 | if (Argc > 1 && name) | |
59 | printf("==> %s <==\n", name); | |
60 | copyout(linecnt); | |
61 | fflush(stdout); | |
62 | } while (argc > 0); | |
63 | } | |
64 | ||
65 | copyout(cnt) | |
66 | register int cnt; | |
67 | { | |
68 | register int c; | |
69 | char lbuf[BUFSIZ]; | |
70 | ||
71 | while (cnt > 0 && fgets(lbuf, sizeof lbuf, stdin) != 0) { | |
72 | printf("%s", lbuf); | |
73 | fflush(stdout); | |
74 | cnt--; | |
75 | } | |
76 | } | |
77 | ||
78 | getnum(cp) | |
79 | register char *cp; | |
80 | { | |
81 | register int i; | |
82 | ||
83 | for (i = 0; *cp >= '0' && *cp <= '9'; cp++) | |
84 | i *= 10, i += *cp - '0'; | |
85 | if (*cp) { | |
86 | fprintf(stderr, "Badly formed number\n"); | |
87 | exit(1); | |
88 | } | |
89 | return (i); | |
90 | } |