Linking the static version of a library instead of the dynamic one

I am trying to use libjpeg in my application. Making the project yields a libjpeg.a in .libs folder. What I would like to do is to use this file in the linkage stage. I have tried the following: I copied the libjpeg.a into the folder where my C code resides. Trying to link with

gcc libjpeg.a mycode.c -o executable_name

fails. If I do gcc -ljpeg mycode.c, the compilation is successful when I change my header to point to instead of "libjpeg.h"开发者_如何转开发, but this obviously links to the system-wide dynamic version of the library.

Trying to link with relative or absolute path also fails:

gcc ./libjpeg.a mycode.c -o executable_name

I have tried the static option as well:

gcc -static libjpeg.a mycode.c -o executable_name

The linker error is the following:

Linking...
gcc -std=c99 -Wall -Wextra -g -pedantic ./libjpeg.a ./libjpeg.a -lm obj/read_jpeg.o obj/utils.o -o test_jpeg
obj/read_jpeg.o: In function `read_JPEG_file':
/home/ustun/Downloads/jpeg_test/read_jpeg.c:37: undefined reference to `jpeg_std_error'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:45: undefined reference to `jpeg_CreateDecompress'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:46: undefined reference to `jpeg_stdio_src'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:47: undefined reference to `jpeg_read_header'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:48: undefined reference to `jpeg_start_decompress'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:62: undefined reference to `jpeg_read_scanlines'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:74: undefined reference to `jpeg_finish_decompress'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:75: undefined reference to `jpeg_destroy_decompress'
obj/read_jpeg.o: In function `read_JPEG_file_props':
/home/ustun/Downloads/jpeg_test/read_jpeg.c:93: undefined reference to `jpeg_std_error'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:100: undefined reference to `jpeg_CreateDecompress'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:101: undefined reference to `jpeg_stdio_src'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:102: undefined reference to `jpeg_read_header'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:103: undefined reference to `jpeg_start_decompress'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:113: undefined reference to `jpeg_read_scanlines'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:116: undefined reference to `jpeg_finish_decompress'
/home/ustun/Downloads/jpeg_test/read_jpeg.c:117: undefined reference to `jpeg_destroy_decompress'
collect2: ld returned 1 exit status
make: *** [test_jpeg] Error 1

You can download a simple project with a Makefile here.

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You'd have to give the full path to libjpeg.a, If you have libjpeg.a in a .libs folder relative to where you compile:

gcc  mycode.c -o executable_name .libs/libjpeg.a

If your special libjpeg.a is elsewhere, give a full path to it.

If this fails, you have to tell us what happens. (the details are important, so please copy paste the exact errors and the exact command line that is run).

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You need to use -static:

gcc -static -o exec_name mycode.c -ljpeg

No need to copy the archive (.a). You could have found out by reading man ld.

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This may help you if you have the same problem as mine. In my system, I have

libjpeg.so.62 -> libjpeg.so.62.0.0 libjpeg.so.62.0.0

After I added symbolic link:

sudo ln -s libjpeg.so.62 libjpeg.so

My problem got solved.