xref: /titanic_41/usr/src/lib/libcmd/common/dirname.c (revision d29f5a711240f866521445b1656d114da090335e)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *           Copyright (c) 1992-2007 AT&T Knowledge Ventures            *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                      by AT&T Knowledge Ventures                      *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                                                                      *
20 ***********************************************************************/
21 #pragma prototyped
22 /*
23  * David Korn
24  * AT&T Bell Laboratories
25  *
26  * dirname path [suffix]
27  *
28  * print the dirname of a pathname
29  */
30 
31 static const char usage[] =
32 "[-?\n@(#)$Id: dirname (AT&T Research) 2000-03-07 $\n]"
33 USAGE_LICENSE
34 "[+NAME?dirname - return directory portion of file name]"
35 "[+DESCRIPTION?\bdirname\b treats \astring\a as a file name and returns "
36 	"the name of the directory containing the file name by deleting "
37 	"the last component from \astring\a.]"
38 "[+?If \astring\a consists solely of \b/\b characters the output will "
39 	"be a single \b/\b unless \bPATH_LEADING_SLASHES\b returned by "
40 	"\bgetconf\b(1) is \b1\b and \astring\a consists of multiple "
41 	"\b/\b characters in which case \b//\b will be output.  "
42 	"Otherwise, trailing \b/\b characters are removed, and if "
43 	"there are no remaining \b/\b characters in \astring\a, "
44 	"the string \b.\b will be written to standard output.  "
45 	"Otherwise, all characters following the last \b/\b are removed. "
46 	"If the remaining string consists solely of \b/\b characters, "
47 	"the output will be as if the original string had consisted solely "
48 	"as \b/\b characters as described above.  Otherwise, all "
49 	"trailing slashes are removed and the output will be this string "
50 	"unless this string is empty.  If empty the output will be \b.\b.]"
51 "\n"
52 "\n string\n"
53 "\n"
54 "[+EXIT STATUS?]{"
55         "[+0?Successful Completion.]"
56         "[+>0?An error occurred.]"
57 "}"
58 "[+SEE ALSO?\bbasename\b(1), \bgetconf\b(1), \bdirname\b(3)]"
59 ;
60 
61 #include <cmd.h>
62 
63 static void l_dirname(register Sfio_t *outfile, register const char *pathname)
64 {
65 	register const char  *last;
66 	/* go to end of path */
67 	for(last=pathname; *last; last++);
68 	/* back over trailing '/' */
69 	while(last>pathname && *--last=='/');
70 	/* back over non-slash chars */
71 	for(;last>pathname && *last!='/';last--);
72 	if(last==pathname)
73 	{
74 		/* all '/' or "" */
75 		if(*pathname!='/')
76 			last = pathname = ".";
77 	}
78 	else
79 	{
80 		/* back over trailing '/' */
81 		for(;*last=='/' && last > pathname; last--);
82 	}
83 	/* preserve // */
84 	if(last!=pathname && pathname[0]=='/' && pathname[1]=='/')
85 	{
86 		while(pathname[2]=='/' && pathname<last)
87 			pathname++;
88 		if(last!=pathname && pathname[0]=='/' && pathname[1]=='/' && *astconf("PATH_LEADING_SLASHES",NiL,NiL)!='1')
89 			pathname++;
90 	}
91 	sfwrite(outfile,pathname,last+1-pathname);
92 	sfputc(outfile,'\n');
93 }
94 
95 int
96 b_dirname(int argc,register char *argv[], void* context)
97 {
98 	register int n;
99 
100 	cmdinit(argc, argv, context, ERROR_CATALOG, 0);
101 	while (n = optget(argv, usage)) switch (n)
102 	{
103 	case ':':
104 		error(2, "%s", opt_info.arg);
105 		break;
106 	case '?':
107 		error(ERROR_usage(2), "%s", opt_info.arg);
108 		break;
109 	}
110 	argv += opt_info.index;
111 	argc -= opt_info.index;
112 	if(error_info.errors || argc != 1)
113 		error(ERROR_usage(2),"%s", optusage(NiL));
114 	l_dirname(sfstdout,argv[0]);
115 	return(0);
116 }
117