1b30d1939SAndy Fiddaman /***********************************************************************
2b30d1939SAndy Fiddaman * *
3b30d1939SAndy Fiddaman * This software is part of the ast package *
4*d6f391efSAndy Fiddaman * Copyright (c) 1992-2013 AT&T Intellectual Property *
5b30d1939SAndy Fiddaman * and is licensed under the *
6b30d1939SAndy Fiddaman * Eclipse Public License, Version 1.0 *
7b30d1939SAndy Fiddaman * by AT&T Intellectual Property *
8b30d1939SAndy Fiddaman * *
9b30d1939SAndy Fiddaman * A copy of the License is available at *
10b30d1939SAndy Fiddaman * http://www.eclipse.org/org/documents/epl-v10.html *
11b30d1939SAndy Fiddaman * (with md5 checksum b35adb5213ca9657e911e9befb180842) *
12b30d1939SAndy Fiddaman * *
13b30d1939SAndy Fiddaman * Information and Software Systems Research *
14b30d1939SAndy Fiddaman * AT&T Research *
15b30d1939SAndy Fiddaman * Florham Park NJ *
16b30d1939SAndy Fiddaman * *
17*d6f391efSAndy Fiddaman * Glenn Fowler <glenn.s.fowler@gmail.com> *
18*d6f391efSAndy Fiddaman * David Korn <dgkorn@gmail.com> *
19b30d1939SAndy Fiddaman * *
20b30d1939SAndy Fiddaman ***********************************************************************/
21b30d1939SAndy Fiddaman #pragma prototyped
22b30d1939SAndy Fiddaman /*
23b30d1939SAndy Fiddaman * David Korn
24b30d1939SAndy Fiddaman * AT&T Bell Laboratories
25b30d1939SAndy Fiddaman *
26b30d1939SAndy Fiddaman * output the beginning portion of one or more files
27b30d1939SAndy Fiddaman */
28b30d1939SAndy Fiddaman
29b30d1939SAndy Fiddaman static const char usage[] =
30*d6f391efSAndy Fiddaman "[-n?\n@(#)$Id: head (AT&T Research) 2013-09-19 $\n]"
31b30d1939SAndy Fiddaman USAGE_LICENSE
32b30d1939SAndy Fiddaman "[+NAME?head - output beginning portion of one or more files ]"
33b30d1939SAndy Fiddaman "[+DESCRIPTION?\bhead\b copies one or more input files to standard "
34b30d1939SAndy Fiddaman "output stopping at a designated point for each file or to the end of "
35b30d1939SAndy Fiddaman "the file whichever comes first. Copying ends at the point indicated by "
36b30d1939SAndy Fiddaman "the options. By default a header of the form \b==> \b\afilename\a\b "
37b30d1939SAndy Fiddaman "<==\b is output before all but the first file but this can be changed "
38b30d1939SAndy Fiddaman "with the \b-q\b and \b-v\b options.]"
39b30d1939SAndy Fiddaman "[+?If no \afile\a is given, or if the \afile\a is \b-\b, \bhead\b "
40b30d1939SAndy Fiddaman "copies from standard input starting at the current location.]"
41b30d1939SAndy Fiddaman "[+?The option argument for \b-c\b, and \b-s\b can optionally be "
42b30d1939SAndy Fiddaman "followed by one of the following characters to specify a different unit "
43b30d1939SAndy Fiddaman "other than a single byte:]"
44b30d1939SAndy Fiddaman "{"
45b30d1939SAndy Fiddaman "[+b?512 bytes.]"
46b30d1939SAndy Fiddaman "[+k?1-killobyte.]"
47b30d1939SAndy Fiddaman "[+m?1-megabyte.]"
48b30d1939SAndy Fiddaman "}"
49b30d1939SAndy Fiddaman "[+?For backwards compatibility, \b-\b\anumber\a is equivalent to \b-n\b "
50b30d1939SAndy Fiddaman "\anumber\a.]"
51b30d1939SAndy Fiddaman "[n:lines?Copy \alines\a lines from each file.]#[lines:=10]"
52b30d1939SAndy Fiddaman "[c:bytes?Copy \achars\a bytes from each file.]#[chars]"
53b30d1939SAndy Fiddaman "[q:quiet|silent?Never ouput filename headers.]"
54b30d1939SAndy Fiddaman "[s:skip?Skip \askip\a characters or lines from each file before "
55b30d1939SAndy Fiddaman "copying.]#[skip]"
56b30d1939SAndy Fiddaman "[v:verbose?Always ouput filename headers.]"
57b30d1939SAndy Fiddaman "\n\n"
58b30d1939SAndy Fiddaman "[ file ... ]"
59b30d1939SAndy Fiddaman "\n\n"
60b30d1939SAndy Fiddaman "[+EXIT STATUS?]"
61b30d1939SAndy Fiddaman "{"
62b30d1939SAndy Fiddaman "[+0?All files copied successfully.]"
63b30d1939SAndy Fiddaman "[+>0?One or more files did not copy.]"
64b30d1939SAndy Fiddaman "}"
65b30d1939SAndy Fiddaman "[+SEE ALSO?\bcat\b(1), \btail\b(1)]"
66b30d1939SAndy Fiddaman ;
67b30d1939SAndy Fiddaman
68b30d1939SAndy Fiddaman #include <cmd.h>
69b30d1939SAndy Fiddaman
70b30d1939SAndy Fiddaman int
b_head(int argc,register char ** argv,Shbltin_t * context)71b30d1939SAndy Fiddaman b_head(int argc, register char** argv, Shbltin_t* context)
72b30d1939SAndy Fiddaman {
73b30d1939SAndy Fiddaman static const char header_fmt[] = "\n==> %s <==\n";
74b30d1939SAndy Fiddaman
75b30d1939SAndy Fiddaman register Sfio_t* fp;
76b30d1939SAndy Fiddaman register char* cp;
77b30d1939SAndy Fiddaman register off_t keep = 10;
78b30d1939SAndy Fiddaman register off_t skip = 0;
79b30d1939SAndy Fiddaman register int delim = '\n';
80*d6f391efSAndy Fiddaman off_t moved;
81b30d1939SAndy Fiddaman int header = 1;
82b30d1939SAndy Fiddaman char* format = (char*)header_fmt+1;
83b30d1939SAndy Fiddaman
84b30d1939SAndy Fiddaman cmdinit(argc, argv, context, ERROR_CATALOG, 0);
85b30d1939SAndy Fiddaman for (;;)
86b30d1939SAndy Fiddaman {
87b30d1939SAndy Fiddaman switch (optget(argv, usage))
88b30d1939SAndy Fiddaman {
89b30d1939SAndy Fiddaman case 'c':
90b30d1939SAndy Fiddaman delim = -1;
91b30d1939SAndy Fiddaman /*FALLTHROUGH*/
92b30d1939SAndy Fiddaman case 'n':
93b30d1939SAndy Fiddaman if (opt_info.offset && argv[opt_info.index][opt_info.offset] == 'c')
94b30d1939SAndy Fiddaman {
95b30d1939SAndy Fiddaman delim = -1;
96b30d1939SAndy Fiddaman opt_info.offset++;
97b30d1939SAndy Fiddaman }
98b30d1939SAndy Fiddaman if ((keep = opt_info.number) <=0)
99b30d1939SAndy Fiddaman error(2, "%s: %I*d: positive numeric option argument expected", opt_info.name, sizeof(keep), keep);
100b30d1939SAndy Fiddaman continue;
101b30d1939SAndy Fiddaman case 'q':
102b30d1939SAndy Fiddaman header = argc;
103b30d1939SAndy Fiddaman continue;
104b30d1939SAndy Fiddaman case 'v':
105b30d1939SAndy Fiddaman header = 0;
106b30d1939SAndy Fiddaman continue;
107b30d1939SAndy Fiddaman case 's':
108b30d1939SAndy Fiddaman skip = opt_info.number;
109b30d1939SAndy Fiddaman continue;
110b30d1939SAndy Fiddaman case '?':
111b30d1939SAndy Fiddaman error(ERROR_usage(2), "%s", opt_info.arg);
112b30d1939SAndy Fiddaman continue;
113b30d1939SAndy Fiddaman case ':':
114b30d1939SAndy Fiddaman error(2, "%s", opt_info.arg);
115b30d1939SAndy Fiddaman continue;
116b30d1939SAndy Fiddaman }
117b30d1939SAndy Fiddaman break;
118b30d1939SAndy Fiddaman }
119b30d1939SAndy Fiddaman argv += opt_info.index;
120b30d1939SAndy Fiddaman argc -= opt_info.index;
121b30d1939SAndy Fiddaman if (error_info.errors)
122b30d1939SAndy Fiddaman error(ERROR_usage(2), "%s", optusage(NiL));
123b30d1939SAndy Fiddaman if (cp = *argv)
124b30d1939SAndy Fiddaman argv++;
125b30d1939SAndy Fiddaman do
126b30d1939SAndy Fiddaman {
127b30d1939SAndy Fiddaman if (!cp || streq(cp, "-"))
128b30d1939SAndy Fiddaman {
129b30d1939SAndy Fiddaman cp = "/dev/stdin";
130b30d1939SAndy Fiddaman fp = sfstdin;
131b30d1939SAndy Fiddaman sfset(fp, SF_SHARE, 1);
132b30d1939SAndy Fiddaman }
133b30d1939SAndy Fiddaman else if (!(fp = sfopen(NiL, cp, "r")))
134b30d1939SAndy Fiddaman {
135b30d1939SAndy Fiddaman error(ERROR_system(0), "%s: cannot open", cp);
136b30d1939SAndy Fiddaman continue;
137b30d1939SAndy Fiddaman }
138b30d1939SAndy Fiddaman if (argc > header)
139b30d1939SAndy Fiddaman sfprintf(sfstdout, format, cp);
140b30d1939SAndy Fiddaman format = (char*)header_fmt;
141b30d1939SAndy Fiddaman if (skip > 0)
142*d6f391efSAndy Fiddaman {
143*d6f391efSAndy Fiddaman if ((moved = sfmove(fp, NiL, skip, delim)) < 0 && !ERROR_PIPE(errno) && errno != EINTR)
144*d6f391efSAndy Fiddaman error(ERROR_system(0), "%s: skip error", cp);
145*d6f391efSAndy Fiddaman if (delim >= 0 && moved < skip)
146*d6f391efSAndy Fiddaman goto next;
147*d6f391efSAndy Fiddaman }
148*d6f391efSAndy Fiddaman if ((moved = sfmove(fp, sfstdout, keep, delim)) < 0 && !ERROR_PIPE(errno) && errno != EINTR ||
149*d6f391efSAndy Fiddaman delim >= 0 && moved < keep && sfmove(fp, sfstdout, SF_UNBOUND, -1) < 0 && !ERROR_PIPE(errno) && errno != EINTR)
150b30d1939SAndy Fiddaman error(ERROR_system(0), "%s: read error", cp);
151*d6f391efSAndy Fiddaman next:
152b30d1939SAndy Fiddaman if (fp != sfstdin)
153b30d1939SAndy Fiddaman sfclose(fp);
154b30d1939SAndy Fiddaman } while (cp = *argv++);
155b30d1939SAndy Fiddaman if (sfsync(sfstdout))
156b30d1939SAndy Fiddaman error(ERROR_system(0), "write error");
157b30d1939SAndy Fiddaman return error_info.errors != 0;
158b30d1939SAndy Fiddaman }
159