1lfc_perl(3) Perl Programmers Reference Guide
2lfc_perl(3)
3[1mNAME[0m
7 lfc ‐ Perl interface to the LFC
8[1mSYNOPSIS[0m
10 [1muse lfc;[0m
11 [1mprintf "CNS_LIST_BEGIN is %d0, $lfc::CNS_LIST_BEGIN;[0m
12[1mDESCRIPTION[0m
14 The lfc module permits you to access the LFC client inter‐
15face from perl
16 programs. The lfc module is a swig wrapping of the stan‐
17dard C inter‐
18 face. For detailed descriptions of each function see
19the individual
20 man page of each function.
21 There follows a series of examples of how to use selected
23functions and
24 how to retrieve the information returned by them: Exam‐
25ples are finding
26 the GUID of an existing entry, listing the replicas of a
27given GUID and
28 setting and retrieving the comment associated with an en‐
29try.
30[1mEXAMPLE[0m
32 #!/usr/bin/perl ‐w
33 use strict;
34 use lfc;
35 # stat an existing entry in the LFC and print the GUID
37 my ($name,$stat,$guid,$res);
38 $name = "/grid/dteam/my.test";
39 $stat = lfcc::new_lfc_filestatg();
41 $res = lfc::lfc_statg($name,undef,$stat);
42 if ($res == 0) {
44 $guid = lfcc::lfc_filestatg_guid_get($stat);
45 print "The GUID for $name is $guid0;
46 } else {
47 my $err_num = $lfc::serrno;
48 my $err_string = lfc::sstrerror($err_num);
49 print "There was an error while looking for $name: Error
50$err_num ($err_string)0;
51 exit(1);
52 }
53 lfcc::delete_lfc_filestatg($stat);
54[1mEXAMPLE[0m
56 #!/usr/bin/perl ‐w
57 use strict;
58 use lfc;
59 # list the replicas of a given entry, starting from the
61GUID
62 my ($guid,$listp,$flag,$num_replicas);
63 $guid = "6a3164e0‐a4d7‐4abe‐9f76‐e3b8882735d1";
64 $listp = lfcc::new_lfc_list();
66 $flag = $lfc::CNS_LIST_BEGIN;
67 print "Listing replicas for GUID $guid:0;
69 $num_replicas=0;
71 while(1) {
73 my $res = lfc::lfc_listreplica(un‐
74def,$guid,$flag,$listp);
75 $flag = $lfc::CNS_LIST_CONTINUE;
76 if (!defined $res) {
78 last;
79 } else {
80 my $rep_name = lfcc::lfc_filereplica_sfn_get($res);
81 print "Replica: $rep_name0;
82 $num_replicas++;
83 }
84 }
85 lfc::lfc_listreplica(un‐
86def,$guid,$lfc::CNS_LIST_END,$listp);
87 lfcc::delete_lfc_list($listp);
88 print "Found $num_replicas replica(s)0;
90[1mEXAMPLE[0m
92 #!/usr/bin/perl ‐w
93 use strict;
94 use lfc;
95 # setting and retrieving a comment on a file
97 my ($file,$res,$bufspec,$buffer,$comment);
98 $file = "/grid/dteam/my.test";
99 $comment = "MyComment";
101 $res = lfc::lfc_setcomment($file,$comment);
102 if ($res != 0) {
104 my $err_num = $lfc::serrno;
105 my $err_string = lfc::sstrerror($err_num);
106 print "Problem while setting comment for $file: Error
107$err_num ($err_string)0;
108 exit(1);
109 }
110 $bufspec = "x".($lfc::CA_MAXCOMMENTLEN+1);
112 $buffer = pack($bufspec);
113 $res = lfc::lfc_getcomment($file,$buffer);
114 if ($res != 0) {
116 my $err_num = $lfc::serrno;
117 my $err_string = lfc::sstrerror($err_num);
118 print "Problem while reading the comment for $file: Er‐
119ror $err_num ($err_string)0;
120 exit(1);
121 }
122 $comment = unpack("Z*", $buffer);
124 print "Read back comment $comment0;
125[1mNOTES[0m
127 The current interface to the [1mlfc_getcom‐
128ment(3)[22m, [1mlfc_getcwd(3)[22m,
129 [1mlfc_readlink(3)[22m, [1mlfc_seterrbuf(3) [22mrequires
130the passing of a suitably
131 allocated buffer (in a similar way to the C functions).
132However this is
133 rather non standard in PERL. A future version of lfc perl
134interface may
135 do away with the need to setup the buffer before
136the call and to
137 explicitly unpack the result afterwards.
138[1mSEE ALSO[0m
140 [1mLFC C interface man pages[0m
141LFC $Date: 2007/02/23 10:03:07 $
145lfc_perl(3)
146