Login or Register to Ask a Question and Join Our Community


UNIX for Advanced & Expert Users

dlsym...error

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Top Forums UNIX for Advanced & Expert Users dlsym...error
# 1  
Old 09-20-2005
Network dlsym...error
Hi,

I have ftp.so file which on nm gives the following table....

[138] |0x0000c4f8|0x000000f0|FUNC |LOCL |0 |14 |ftp_active
[160] |0x0000c00c|0x000000f0|FUNC |LOCL |0 |14 |ftp_ascii
[135] |0x0000c0fc|0x000000f0|FUNC |LOCL |0 |14 |ftp_binary
[163] |0x0000a8e0|0x000001a8|FUNC |LOCL |0 |14 |ftp_cd
[130] |0x0000bf20|0x000000ec|FUNC |LOCL |0 |14 |ftp_close
.
.
[178] |0x00000000|0x00000000|FUNC |GLOB |0 |UNDEF |Ls__9FTPClientRQ29FTPCl
ient8FileListPCc [FTPClient::Ls(FTPClient::FileList &, char const *)]

Now using dlopen and doing a dlsym on "ftp_cd", "ftp_ascii" is gives an error
saying
dlsym Couldn't find ftp_cd: ld.so.1: cor: fatal: ftp_cd: can't find symbol
while for "FTPClient::Ls(FTPClient::FileList &, char const *)" it does not give any error.
Can any one please tell me why and how can i get reference to these functions.

my code :
.
.
handle = dlopen("ftp.so",RTLD_NOW);
if(!handle) {
// print error..
}
dlerror();
fnc = ((int*)()(int)) dlsym(handle,FN_Name[i]);
if((error=dlerror())) {
// print error
}

.
.
here :
FN_Name[i] = contains mangled name entries from output of "nm" shown above.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Beginners Questions & Answers

Print Error in Console and both Error & Output in Log file - UNIX

I am writing a shell script with 2 run time arguments. During the execution if i got any error, then it needs to redirected to a error file and in console. Also both error and output to be redirected to a log file. But i am facing the below error. #! /bin/sh errExit () { errMsg=`cat... (1 Reply)
Discussion started by: sarathy_a35
1 Replies

2. Shell Programming and Scripting

IF section problem. syntax error: unexpected end of file error

Hello, I have another problem with my script. Please accept my apologies, but I am really nooby in sh scripts. I am writing it for first time. My script: returned=`tail -50 SapLogs.log | grep -i "Error"` echo $returned if ; then echo "There is no errors in the logs" fi And after... (10 Replies)
Discussion started by: jedzio
10 Replies

3. Solaris

Rpcinfo: can't contact portmapper: RPC: Authentication error; why = Failed (unspecified error)

I have two servers with a fresh install of Solaris 11, and having problems when doing rpcinfo between them. There is no firewall involved, so everything should theoretically be getting through. Does anyone have any ideas? I did a lot of Google searches, and haven't found a working solution yet. ... (2 Replies)
Discussion started by: christr
2 Replies

4. Shell Programming and Scripting

What is this error log = hda: irq timeout: error=0x00 and how to solve?

what is this error log = hda: irq timeout: error=0x00 and how to solve? every day upon checking the logs i see this error. hda: irq timeout: error=0x00 hda: irq timeout: error=0x00 hda: irq timeout: error=0x00 hda: irq timeout: error=0x00 hw_client: segfault at 0000000000000046 rip... (3 Replies)
Discussion started by: avtalan
3 Replies

5. UNIX for Dummies Questions & Answers

> 5 ")syntax error: operand expected (error token is " error

im kinda new to shell scripting so i need some help i try to run this script and get the error code > 5 ")syntax error: operand expected (error token is " the code for the script is #!/bin/sh # # script to see if the given value is correct # # Define errors ER_AF=86 # Var is... (4 Replies)
Discussion started by: metal005
4 Replies

6. UNIX for Dummies Questions & Answers

dlsym() returns 0 for an existing function

Sometimes I observe this in gdb: (gdb) br my_function Breakpoint .. at 0x...: file ..., line ... i.e., "my_function" does exist in the current executable. however, dlsym does not find it: (gdb) p dlsym(0,"my_function") $6 = 0 This is a C program; dlsym does find other defined functions and... (2 Replies)
Discussion started by: sds
2 Replies

7. AIX

nim mksysb error :/usr/bin/savevg[33]: 1016,07: syntax error

-------------------------------------------------------------------------------- Hello, help me please. I am trying to create a mksysb bakup using nim. I am geting this error, how to correct it ? : Command : failed stdout: yes stderr: no... (9 Replies)
Discussion started by: astjen
9 Replies

8. UNIX for Advanced & Expert Users

VSI-FAX error - Cannot login to server and Connecto error to host

I encounters a VSIFAX related error: vfxstat: Cannot login to server on rsac3: Connect error to host 172.16.1.45: Invalid argument It started happening last night with a core dump. Then we can't start VSIFAX again. I am runing VSI-FAX 4.2 on AIX box (0 Replies)
Discussion started by: b_jin
0 Replies

9. UNIX for Dummies Questions & Answers

awk Shell Script error : "Syntax Error : `Split' unexpected

hi there i write one awk script file in shell programing the code is related to dd/mm/yy to month, day year format but i get an error please can anybody help me out in this problem ?????? i give my code here including error awk ` # date-month -- convert mm/dd/yy to month day,... (2 Replies)
Discussion started by: Herry
2 Replies

10. UNIX for Dummies Questions & Answers

Error: Internal system error: Unable to initialize standard output file

Hey guys, need some help. Running AIX Version 5.2 and one of our cron jobs is writing errors to a log file. Any ideas on the following error message. Error: Internal system error: Unable to initialize standard output file I'm guessing more info might be needed, so let me know. Thanks (2 Replies)
Discussion started by: firkus
2 Replies
Login or Register to Ask a Question

LEARN ABOUT PHP

dlsym

DLSYM(3)						     Linux Programmer's Manual							  DLSYM(3)

NAME

       dlsym, dlvsym - obtain address of a symbol in a shared object or executable

SYNOPSIS

       #include <dlfcn.h>

       void *dlsym(void *handle, const char *symbol);

       #define _GNU_SOURCE
       #include <dlfcn.h>

       void *dlvsym(void *handle, char *symbol, char *version);

       Link with -ldl.

DESCRIPTION

       The function dlsym() takes a "handle" of a dynamic loaded shared object returned by dlopen(3) along with a null-terminated symbol name, and
       returns the address where that symbol is loaded into memory.  If the symbol is not found, in the specified object  or  any  of  the  shared
       objects that were automatically loaded by dlopen(3) when that object was loaded, dlsym() returns NULL.  (The search performed by dlsym() is
       breadth first through the dependency tree of these shared objects.)

       Since the value of the symbol could actually be NULL (so that a NULL return from dlsym() need not indicate an error), the  correct  way	to
       test  for  an  error is to call dlerror(3) to clear any old error conditions, then call dlsym(), and then call dlerror(3) again, saving its
       return value into a variable, and check whether this saved value is not NULL.

       There are two special pseudo-handles that may be specified in handle:

       RTLD_DEFAULT
	      Find the first occurrence of the desired symbol using the default shared object search order.  The search will include  global  sym-
	      bols  in the executable and its dependencies, as well as symbols in shared objects that were dynamically loaded with the RTLD_GLOBAL
	      flag.

       RTLD_NEXT
	      Find the next occurrence of the desired symbol in the search order after the current object.  This allows one to provide	a  wrapper
	      around  a  function  in  another shared object, so that, for example, the definition of a function in a preloaded shared object (see
	      LD_PRELOAD in ld.so(8)) can find and invoke the "real" function provided in another shared object (or for that  matter,  the  "next"
	      definition of the function in cases where there are multiple layers of preloading).

       The _GNU_SOURCE feature test macro must be defined in order to obtain the definitions of RTLD_DEFAULT and RTLD_NEXT from <dlfcn.h>.

       The function dlvsym() does the same as dlsym() but takes a version string as an additional argument.

RETURN VALUE

       On  success,  these functions return the address associated with symbol.  On failure, they return NULL; the cause of the error can be diag-
       nosed using dlerror(3).

VERSIONS

       dlsym() is present in glibc 2.0 and later.  dlvsym() first appeared in glibc 2.1.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       +------------------+---------------+---------+
       |Interface	  | Attribute	  | Value   |
       +------------------+---------------+---------+
       |dlsym(), dlvsym() | Thread safety | MT-Safe |
       +------------------+---------------+---------+
CONFORMING TO

       POSIX.1-2001 describes dlsym().	The dlvsym() function is a GNU extension.

NOTES

   History
       The dlsym() function is part of the dlopen API, derived from SunOS.  That system does not have dlvsym().

EXAMPLE

       See dlopen(3).

SEE ALSO

       dl_iterate_phdr(3), dladdr(3), dlerror(3), dlinfo(3), dlopen(3), ld.so(8)

COLOPHON

       This page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and  the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

Linux								    2017-09-15								  DLSYM(3)