A library is a collection of functionality that programs can use. They can be dynamically loaded by a program, or they may be compiled into the program.
Questions tagged [libraries]
559 questions
164
votes
9 answers
How to find out the dynamic libraries executables loads when run?
I want to find out the list of dynamic libraries a binary loads when run (With their full paths). I am using CentOS 6.0. How to do this?
nakiya
96
votes
2 answers
Use shared libraries in /usr/local/lib
I have build some libraries from sources, and the files after make install are in /usr/local/lib
For example, in my case I have the file libodb-2.2.so which is in this directory.
However when I launch the executable that has linked with libodb, I…
Stephane Rolland
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91
votes
2 answers
What is the difference between .a and .so file?
As far as I understand they are libraries, but what is the difference between the two?
Erik B
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68
votes
5 answers
Viewing Linux Library / Executable version info
In Windows, EXE and DLL have version info, including at least the following fields:
file version
product version
internal name
product name
copyright
In Linux Library / Executable:
Which fields are present?
How to view such info?
What…
linquize
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65
votes
2 answers
Why are shared libraries executable?
Why have almost all the shared libraries in /usr/lib/ have the executable permission bit set? I don't see any use case for executing them. Some do manage to hook-up some form of main function to print a short copyright and version note, but many…
Tadeusz A. Kadłubowski
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65
votes
1 answer
What is /lib64/ld-linux-x86-64.so.2 and why can it be used to execute file?
Recently, I have learned a trick that if a file lacks executable permissions, we can run that file by using /lib64/ld-linux-x86-64.so.2.
For example, to restore x permission for
-rw-r--r-- 1 root root 59K Mar 1 2017 /bin/chmod
we can…
Federal Reserve
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53
votes
1 answer
Difference between lib, lib32, lib64, libx32, and libexec
My 64 bit Ubuntu 13.04 system has the following directories in /:
lib
lib32
lib64
libx32
libexec
In the /usr directory there is:
lib
lib32
libx32
libexec
This seemed like something that could be easily answered with a search, but I found nothing…
gsgx
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50
votes
1 answer
Loading of shared libraries and RAM usage
I'm wondering about the way Linux manages shared libraries. (actually I'm talking about Maemo Fremantle, a Debian-based distro released in 2009 running on 256MB RAM).
Let's assume we have two executables linking to libQtCore.so.4 and using its…
marmistrz
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43
votes
4 answers
How to check if a shared library is installed?
My question originates from my problem in getting ffmpeg started.
I have installed ffmpeg and it is displayed as installed:
whereis ffmpeg
ffmpeg: /usr/bin/ffmpeg /usr/bin/X11/ffmpeg /usr/share/ffmpeg /usr/share/man/man1/ffmpeg.1.gz
Later, I…
Abdul Al Hazred
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38
votes
1 answer
What does libgcc_s.so contain?
I tried running objdump on the lib to figure it out without success. Is there a way to find out what a library does?
celavek
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34
votes
2 answers
Changing linked library for a given executable (CentOs 6)
I have an executable linked like this:
$ ldd a.out
libboost_system-mt.so.1.47.0 => /usr/lib64/libboost_system-mt.so.1.47.0 (0x00007f4881f56000)
libssl.so.10 => /usr/lib64/libssl.so.10 (0x00007f4881cfb000)
libcrypto.so.10 =>…
Fixee
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33
votes
3 answers
Do C compilers discard unused functions when statically linking to .a file?
Say I have a C program main.c that statically links to libmine.a. Statically linking to a library causes library functions to be embedded into the main executable at compile time.
If libmine.a were to feature functions that weren't used by main.c,…
Izzo
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32
votes
8 answers
ldd tells me my app is "not a dynamic executable"
I have a 32-bit application (called uclsyn) I received from an astronomy professor. I managed to get it running on CentOS a year ago, but now when I am setting up a new CentOS VM, it won't run and I can't work out why. It keeps coming back with…
Carl
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29
votes
8 answers
Stereo "tone-generator" for linux?
Is there something like a stereo (separate left-and right-channel) tone-generator for Linux? Where you can set volume and tone/pitch for each channel, and preferably also set the wave-form (sine, square, sawtooth, ...) and invert one channel (as…
Baard Kopperud
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29
votes
4 answers
How to execute library commands from the shell?
I wanted to simply calculate the length of a string (that is hash value). So, I opened terminal and did this:
$ apropos length
that returned me with a bunch of commands/functions having (3) or (3ssl) appended at the end of them. Now man man gives…
C0deDaedalus
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