linker problem in libxml2

naveenisback · 01-02-2010, 02:29 AM

Hi

OS:ubuntu under AMD 64
language : c/c++

I downloaded libxml2-2.6.31.tar.gz and i installed successfully. my program is like this

Code:

1 #include <stdio.h>
2 #include <libxml/parser.h>
3 #include <libxml/tree.h>
4
5 static void print_element_names(xmlNode * a_node)
6 {
7 xmlNode *cur_node = NULL;
8
9 for (cur_node = a_node; cur_node; cur_node =
cur_node->next) {
10 if (cur_node->type == XML_ELEMENT_NODE) {
11 printf("node type: Element, name: %s\n",
cur_node->name);
12 }
13 print_element_names(cur_node->children);
14 }
15 }
16
17 int main(int argc, char **argv)
18 {
19 xmlDoc *doc = NULL;
20 xmlNode *root_element = NULL;
21
22 if (argc != 2) return(1);
23
24 LIBXML_TEST_VERSION // Macro to check API for match with
// the DLL we are using
25
26 /*parse the file and get the DOM */
27 if (doc = xmlReadFile(argv[1], NULL, 0)) == NULL){
28 printf("error: could not parse file %s\n", argv[1]);
29 exit(-1);
30 }
31
32 /*Get the root element node */
33 root_element = xmlDocGetRootElement(doc);
34 print_element_names(root_element);
35 xmlFreeDoc(doc); // free document
36 xmlCleanupParser(); // Free globals
37 return 0;
38 }

compilation as follows:

Code:

gcc -lxml2 -lm parser.c

but i got following errors

Code:

/tmp/ccEMs4sY.o: In function `example3Func':
parse.c.text+0x2c): undefined reference to `xmlReadMemory'
parse.c.text+0x67): undefined reference to `xmlFreeDoc'
/tmp/ccEMs4sY.o: In function `main':
parse.c.text+0x89): undefined reference to `xmlCheckVersion'
parse.c.text+0xe3): undefined reference to `xmlCleanupParser'
parse.c.text+0xe8): undefined reference to `xmlMemoryDump'
collect2: ld returned 1 exit status

even i included "-lxml2 -lm " linker flags, Im getting the linker error
and note that Im running under 64 bit amd processor.. is this is the problem..
Thanks in advance

Sergei Steshenko · 01-02-2010, 02:44 AM

Quote:

Originally Posted by naveenisback

Hi

OS:ubuntu under AMD 64
language : c/c++

I downloaded libxml2-2.6.31.tar.gz and i installed successfully. my program is like this

Code:

1 #include <stdio.h>
2 #include <libxml/parser.h>
3 #include <libxml/tree.h>
4
5 static void print_element_names(xmlNode * a_node)
6 {
7 xmlNode *cur_node = NULL;
8
9 for (cur_node = a_node; cur_node; cur_node =
cur_node->next) {
10 if (cur_node->type == XML_ELEMENT_NODE) {
11 printf("node type: Element, name: %s\n",
cur_node->name);
12 }
13 print_element_names(cur_node->children);
14 }
15 }
16
17 int main(int argc, char **argv)
18 {
19 xmlDoc *doc = NULL;
20 xmlNode *root_element = NULL;
21
22 if (argc != 2) return(1);
23
24 LIBXML_TEST_VERSION // Macro to check API for match with
// the DLL we are using
25
26 /*parse the file and get the DOM */
27 if (doc = xmlReadFile(argv[1], NULL, 0)) == NULL){
28 printf("error: could not parse file %s\n", argv[1]);
29 exit(-1);
30 }
31
32 /*Get the root element node */
33 root_element = xmlDocGetRootElement(doc);
34 print_element_names(root_element);
35 xmlFreeDoc(doc); // free document
36 xmlCleanupParser(); // Free globals
37 return 0;
38 }

compilation as follows:

Code:

gcc -lxml2 -lm parser.c

but i got following errors

Code:

/tmp/ccEMs4sY.o: In function `example3Func':
parse.c.text+0x2c): undefined reference to `xmlReadMemory'
parse.c.text+0x67): undefined reference to `xmlFreeDoc'
/tmp/ccEMs4sY.o: In function `main':
parse.c.text+0x89): undefined reference to `xmlCheckVersion'
parse.c.text+0xe3): undefined reference to `xmlCleanupParser'
parse.c.text+0xe8): undefined reference to `xmlMemoryDump'
collect2: ld returned 1 exit status

even i included "-lxml2 -lm " linker flags, Im getting the linker error
and note that Im running under 64 bit amd processor.. is this is the problem..
Thanks in advance

Where ?

How do you know linker picks the correct 'libxml2' ?

ta0kira · 01-02-2010, 10:33 AM

You need to put -lxml2 and -lm at the end. gcc looks at them first and finds no dependencies so it skips over them, then it gets to your .c file.
Kevin Barry

naveenisback · 01-03-2010, 11:12 PM

hi

I compiled as follows
"gcc parser.c -lxml2 -lm "

Now im getting errors as follows

/usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../lib/libxml2.a(xmlIO.o): In function `xmlGzfileOpenW':
(.text+0x8f6): undefined reference to `gzdopen'
/usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../lib/libxml2.a(xmlIO.o): In function `xmlGzfileOpenW':
(.text+0x938): undefined reference to `gzopen'
/usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../lib/libxml2.a(xmlIO.o): In function `xmlGzfileOpenW':
(.text+0x952): undefined reference to `gzopen'
/usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../lib/libxml2.a(xmlIO.o): In function `xmlGzfileRead':
(.text+0x962): undefined reference to `gzread'
/usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../lib/libxml2.a(xmlIO.o): In function `xmlGzfileWrite':
(.text+0x982): undefined reference to `gzwrite'
/usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../lib/libxml2.a(xmlIO.o): In function `xmlGzfileClose':
(.text+0x9a5): undefined reference to `gzclose'
/usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../lib/libxml2.a(xmlIO.o): In function `xmlFreeZMemBuff':
(.text+0xa18): undefined reference to `deflateEnd'
/usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../lib/libxml2.a(xmlIO.o): In function `__xmlParserInputBufferCreateFilename':
(.text+0x10aa): undefined reference to `gzread'
/usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../lib/libxml2.a(xmlIO.o): In function `__xmlParserInputBufferCreateFilename':
(.text+0x10d2): undefined reference to `gzrewind'
/usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../lib/libxml2.a(xmlIO.o): In function `xmlIOHTTPCloseWrite':
(.text+0x1abb): undefined reference to `deflate'

I have downloaded libxml2 parser from this link.
http://linux.softpedia.com/progDownl...nload-162.html

do we have different kind of libxml2 parser for 64 bit and 32 bit.
if so, can u tell me where can i download libxml2 for 64 bit amd machine.

Thanks in advance

ta0kira · 01-04-2010, 12:49 AM

It looks like you need to link to a gzip library, also. Maybe you need to add -lgz? That should go after -lxml2.
Kevin Barry

naveenisback · 01-04-2010, 01:19 AM

Hi ta0kira,

Thanks for ur immediate reply.

libxml2 was not completely installed.
So I did sudo apt-get -f install.
Then all the broken softwares upgraded.
Now its working fine without '-lgz'

Thanks

ta0kira · 01-04-2010, 08:00 PM

Yes, that makes more sense than libxml not being hard-lined to libgz, as I implied...
Kevin Barry