14887Schin /***********************************************************************
24887Schin * *
34887Schin * This software is part of the ast package *
4*12068SRoger.Faulkner@Oracle.COM * Copyright (c) 1992-2010 AT&T Intellectual Property *
54887Schin * and is licensed under the *
64887Schin * Common Public License, Version 1.0 *
78462SApril.Chin@Sun.COM * by AT&T Intellectual Property *
84887Schin * *
94887Schin * A copy of the License is available at *
104887Schin * http://www.opensource.org/licenses/cpl1.0.txt *
114887Schin * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
124887Schin * *
134887Schin * Information and Software Systems Research *
144887Schin * AT&T Research *
154887Schin * Florham Park NJ *
164887Schin * *
174887Schin * Glenn Fowler <gsf@research.att.com> *
184887Schin * David Korn <dgk@research.att.com> *
194887Schin * *
204887Schin ***********************************************************************/
214887Schin #pragma prototyped
224887Schin /*
234887Schin * David Korn
244887Schin * AT&T Bell Laboratories
254887Schin *
264887Schin * output the beginning portion of one or more files
274887Schin */
284887Schin
294887Schin static const char usage[] =
308462SApril.Chin@Sun.COM "[-n?\n@(#)$Id: head (AT&T Research) 2006-09-27 $\n]"
314887Schin USAGE_LICENSE
324887Schin "[+NAME?head - output beginning portion of one or more files ]"
334887Schin "[+DESCRIPTION?\bhead\b copies one or more input files to standard "
344887Schin "output stopping at a designated point for each file or to the end of "
354887Schin "the file whichever comes first. Copying ends at the point indicated by "
364887Schin "the options. By default a header of the form \b==> \b\afilename\a\b "
374887Schin "<==\b is output before all but the first file but this can be changed "
384887Schin "with the \b-q\b and \b-v\b options.]"
394887Schin "[+?If no \afile\a is given, or if the \afile\a is \b-\b, \bhead\b "
404887Schin "copies from standard input starting at the current location.]"
414887Schin "[+?The option argument for \b-c\b, and \b-s\b can optionally be "
424887Schin "followed by one of the following characters to specify a different unit "
434887Schin "other than a single byte:]"
444887Schin "{"
454887Schin "[+b?512 bytes.]"
464887Schin "[+k?1-killobyte.]"
474887Schin "[+m?1-megabyte.]"
484887Schin "}"
494887Schin "[+?For backwards compatibility, \b-\b\anumber\a is equivalent to \b-n\b "
504887Schin "\anumber\a.]"
514887Schin "[n:lines?Copy \alines\a lines from each file.]#[lines:=10]"
524887Schin "[c:bytes?Copy \achars\a bytes from each file.]#[chars]"
534887Schin "[q:quiet|silent?Never ouput filename headers.]"
544887Schin "[s:skip?Skip \askip\a characters or lines from each file before "
554887Schin "copying.]#[skip]"
564887Schin "[v:verbose?Always ouput filename headers.]"
574887Schin "\n\n"
584887Schin "[ file ... ]"
594887Schin "\n\n"
604887Schin "[+EXIT STATUS?]"
614887Schin "{"
624887Schin "[+0?All files copied successfully.]"
634887Schin "[+>0?One or more files did not copy.]"
644887Schin "}"
654887Schin "[+SEE ALSO?\bcat\b(1), \btail\b(1)]"
664887Schin ;
674887Schin
684887Schin #include <cmd.h>
694887Schin
704887Schin int
b_head(int argc,register char ** argv,void * context)714887Schin b_head(int argc, register char** argv, void* context)
724887Schin {
734887Schin static const char header_fmt[] = "\n==> %s <==\n";
744887Schin
754887Schin register Sfio_t* fp;
764887Schin register char* cp;
774887Schin register off_t keep = 10;
784887Schin register off_t skip = 0;
794887Schin register int delim = '\n';
804887Schin int header = 1;
814887Schin char* format = (char*)header_fmt+1;
824887Schin
834887Schin cmdinit(argc, argv, context, ERROR_CATALOG, 0);
844887Schin for (;;)
854887Schin {
864887Schin switch (optget(argv, usage))
874887Schin {
884887Schin case 'c':
894887Schin delim = -1;
904887Schin /*FALLTHROUGH*/
914887Schin case 'n':
924887Schin if (opt_info.offset && argv[opt_info.index][opt_info.offset] == 'c')
934887Schin {
944887Schin delim = -1;
954887Schin opt_info.offset++;
964887Schin }
974887Schin if ((keep = opt_info.number) <=0)
984887Schin error(2, "%s: %I*d: positive numeric option argument expected", opt_info.name, sizeof(keep), keep);
994887Schin continue;
1004887Schin case 'q':
1014887Schin header = argc;
1024887Schin continue;
1034887Schin case 'v':
1044887Schin header = 0;
1054887Schin continue;
1064887Schin case 's':
1074887Schin skip = opt_info.number;
1084887Schin continue;
1094887Schin case '?':
1104887Schin error(ERROR_usage(2), "%s", opt_info.arg);
1114887Schin continue;
1124887Schin case ':':
1134887Schin error(2, "%s", opt_info.arg);
1144887Schin continue;
1154887Schin }
1164887Schin break;
1174887Schin }
1184887Schin argv += opt_info.index;
1194887Schin argc -= opt_info.index;
1204887Schin if (error_info.errors)
1214887Schin error(ERROR_usage(2), "%s", optusage(NiL));
1224887Schin if (cp = *argv)
1234887Schin argv++;
1244887Schin do
1254887Schin {
1264887Schin if (!cp || streq(cp, "-"))
1274887Schin {
1284887Schin cp = "/dev/stdin";
1294887Schin fp = sfstdin;
1304887Schin sfset(fp, SF_SHARE, 1);
1314887Schin }
1324887Schin else if (!(fp = sfopen(NiL, cp, "r")))
1334887Schin {
1344887Schin error(ERROR_system(0), "%s: cannot open", cp);
1354887Schin continue;
1364887Schin }
1374887Schin if (argc > header)
1384887Schin sfprintf(sfstdout, format, cp);
1394887Schin format = (char*)header_fmt;
1404887Schin if (skip > 0)
1414887Schin sfmove(fp, NiL, skip, delim);
1424887Schin if (sfmove(fp, sfstdout, keep, delim) < 0 && errno != EPIPE)
1434887Schin error(ERROR_system(0), "%s: read error", cp);
1444887Schin if (fp != sfstdin)
1454887Schin sfclose(fp);
1464887Schin } while (cp = *argv++);
1474887Schin if (sfsync(sfstdout))
1484887Schin error(ERROR_system(0), "write error");
1494887Schin return error_info.errors != 0;
1504887Schin }
151