Question:

This question already has an answer here:

<ul><li> <a href="/questions/9253200/undefined-reference-to-pthread-create-linker-command-option-order-libraries" dir="ltr" rel="nofollow">Undefined reference to 'pthread_create' — linker command option order (libraries before/after object files?) [duplicate]</a> <span class="question-originals-answer-count"> 2 answers </span> </li> </ul>

I have a problem with my S program. I need to compile it with this command:

gcc -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -lglib-2.0 \ -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wall -Wextra -g -std=c99 -lm *.c \ -o generator1_1

I have many error messages like this:

/home/cyrine/Bureau/Seq_GLib2_1_1_Triche/main.c:153: undefined reference to `g_hash_table_lookup' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/main.c:171: undefined reference to `g_hash_table_insert' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/main.c:172: undefined reference to `g_array_append_vals' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/main.c:179: undefined reference to `g_array_append_vals' /tmp/ccVqEbsM.o: In function `main': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/main.c:238: undefined reference to `g_hash_table_new_full' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/main.c:239: undefined reference to `g_hash_table_new_full' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/main.c:263: undefined reference to `g_hash_table_destroy' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/main.c:264: undefined reference to `g_hash_table_destroy' /tmp/cc2UG2Wy.o: In function `fillVFile': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/reader.c:47: undefined reference to `g_strdup' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/reader.c:51: undefined reference to `g_ptr_array_add' /tmp/cctOiTOl.o: In function `calculRegles': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:23: undefined reference to `g_hash_table_get_values' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:48: undefined reference to `g_list_length' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:57: undefined reference to `g_list_sort' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:82: undefined reference to `g_hash_table_new' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:85: undefined reference to `g_array_new' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:110: undefined reference to `g_hash_table_lookup' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:116: undefined reference to `g_hash_table_lookup' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:121: undefined reference to `log2' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:125: undefined reference to `g_array_append_vals' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:128: undefined reference to `g_hash_table_insert' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:139: undefined reference to `g_array_sort' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:167: undefined reference to `g_hash_table_lookup' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:176: undefined reference to `g_hash_table_lookup' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:198: undefined reference to `g_hash_table_destroy' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:199: undefined reference to `g_array_free' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/regles.c:205: undefined reference to `g_list_free' /tmp/cczRKfT8.o: In function `cstSequence1': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/sequence1.c:19: undefined reference to `g_array_new' /tmp/cczRKfT8.o: In function `dstSequence1': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/sequence1.c:26: undefined reference to `g_array_free' /tmp/cczRKfT8.o: In function `hashSeq1Fct': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/sequence1.c:97: undefined reference to `g_str_hash' /tmp/cczRKfT8.o: In function `eqSeq1Fct': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/sequence1.c:113: undefined reference to `g_str_equal' /tmp/cc7ZNuaW.o: In function `cstSequence2': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/sequence2.c:22: undefined reference to `g_array_new' /tmp/cc7ZNuaW.o: In function `dstSequence2': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/sequence2.c:29: undefined reference to `g_array_free' /tmp/cc7ZNuaW.o: In function `hashSeq2Fct': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/sequence2.c:131: undefined reference to `g_str_hash' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/sequence2.c:132: undefined reference to `g_str_hash' /tmp/cc7ZNuaW.o: In function `eqSeq2Fct': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/sequence2.c:152: undefined reference to `g_str_equal' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/sequence2.c:153: undefined reference to `g_str_equal' /tmp/ccY2cdEJ.o: In function `foncteurRetireDoublonsSeq1': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/utils.c:29: undefined reference to `g_array_remove_index' /tmp/ccY2cdEJ.o: In function `foncteurRetireDoublonsSeq2': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/utils.c:52: undefined reference to `g_array_remove_index' /tmp/ccY2cdEJ.o: In function `retireDoublonsLignesSeq1': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/utils.c:66: undefined reference to `g_hash_table_get_values' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/utils.c:68: undefined reference to `g_list_foreach' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/utils.c:70: undefined reference to `g_list_free' /tmp/ccY2cdEJ.o: In function `retireDoublonsLignesSeq2': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/utils.c:75: undefined reference to `g_hash_table_get_values' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/utils.c:77: undefined reference to `g_list_foreach' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/utils.c:79: undefined reference to `g_list_free' /tmp/cc8GGinx.o: In function `cstVFile': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/vfile.c:15: undefined reference to `g_ptr_array_sized_new' /tmp/cc8GGinx.o: In function `dstVFile': /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/vfile.c:26: undefined reference to `g_free' /home/cyrine/Bureau/Seq_GLib2_1_1_Triche/vfile.c:29: undefined reference to `g_ptr_array_free' collect2: ld returned 1 exit status make: *** [all] Error 1

I work with Ubuntu 12.04. Does anyone have any idea?

Include the libraries, specified by -l, after the 'object' files (or source files when you compile the source and link all at once).

You have:

gcc -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include \ -lglib-2.0 \ -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wall -Wextra -g -std=c99 \ -lm *.c -o generator1_1

You need:

gcc -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include \ -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wall -Wextra -g -std=c99 \ *.c -lglib-2.0 -lm -o generator1_1

There may be a few systems where you can specify libraries at arbitrary positions in the linking command line, but 'libraries after object files' has always worked on all the systems I've ever come across.