xref: /netbsd-src/external/ibm-public/postfix/dist/src/global/file_id.c (revision a30b880ed60a24c405edba78187a04247f4d9d33)
1 /*	$NetBSD: file_id.c,v 1.1.1.2 2013/01/02 18:58:58 tron Exp $	*/
2 
3 /*++
4 /* NAME
5 /*	file_id 3
6 /* SUMMARY
7 /*	file ID printable representation
8 /* SYNOPSIS
9 /*	#include <file_id.h>
10 /*
11 /*	const char *get_file_id_fd(fd, long_flag)
12 /*	int	fd;
13 /*	int	long_flag;
14 /*
15 /*	const char *get_file_id_st(st, long_flag)
16 /*	struct stat *st;
17 /*	int	long_flag;
18 /*
19 /*	const char *get_file_id(fd)
20 /*	int	fd;
21 /* DESCRIPTION
22 /*	get_file_id_fd() queries the operating system for the unique
23 /*	file identifier for the specified file descriptor and returns
24 /*	a printable representation.  The result is volatile.  Make
25 /*	a copy if it is to be used for any appreciable amount of
26 /*	time.
27 /*
28 /*	get_file_id_st() returns the unique identifier for the
29 /*	specified file status information.
30 /*
31 /*	get_file_id() provides binary compatibility for old programs.
32 /*	This function should not be used by new programs.
33 /*
34 /*	Arguments:
35 /* .IP fd
36 /*	A valid file descriptor that is associated with an open file.
37 /* .IP st
38 /*	The result from e.g., stat(2) or fstat(2).
39 /* .IP long_flag
40 /*	Encode the result as appropriate for long or short queue
41 /*	identifiers.
42 /* DIAGNOSTICS
43 /*	All errors are fatal.
44 /* LICENSE
45 /* .ad
46 /* .fi
47 /*	The Secure Mailer license must be distributed with this software.
48 /* AUTHOR(S)
49 /*	Wietse Venema
50 /*	IBM T.J. Watson Research
51 /*	P.O. Box 704
52 /*	Yorktown Heights, NY 10598, USA
53 /*--*/
54 
55 /* System library. */
56 
57 #include <sys_defs.h>
58 #include <sys/stat.h>
59 #include <string.h>
60 
61 /* Utility library */
62 
63 #include <msg.h>
64 #include <vstring.h>
65 #include <warn_stat.h>
66 
67 /* Global library. */
68 
69 #define MAIL_QUEUE_INTERNAL
70 #include <mail_queue.h>
71 #include "file_id.h"
72 
73 /* get_file_id - binary compatibility */
74 
get_file_id(int fd)75 const char *get_file_id(int fd)
76 {
77     return (get_file_id_fd(fd, 0));
78 }
79 
80 /* get_file_id_fd - return printable file identifier for file descriptor */
81 
get_file_id_fd(int fd,int long_flag)82 const char *get_file_id_fd(int fd, int long_flag)
83 {
84     struct stat st;
85 
86     if (fstat(fd, &st) < 0)
87 	msg_fatal("fstat: %m");
88     return (get_file_id_st(&st, long_flag));
89 }
90 
91 /* get_file_id_st - return printable file identifier for file status */
92 
get_file_id_st(struct stat * st,int long_flag)93 const char *get_file_id_st(struct stat * st, int long_flag)
94 {
95     static VSTRING *result;
96 
97     if (result == 0)
98 	result = vstring_alloc(1);
99     if (long_flag)
100 	return (MQID_LG_ENCODE_INUM(result, st->st_ino));
101     else
102 	return (MQID_SH_ENCODE_INUM(result, st->st_ino));
103 }
104