Can't link libreadline on Ubuntu 14.04

Question

this may be a very stupid error, but can't find any reference in the web.

I try to compile this bare minimum readline example:

#include <stdio.h>
#include <malloc.h>
#include <readline/readline.h>

void main(void){

char *line;

while( 1==1 ){
    line=readline("enter text>");
    printf("text: %s <\n",line);
    free(line);
    }
}

and got this:

$>cc   -lreadline  read_test.c
/tmp/cc6JYBvf.o: In function `main':
read_test.c:(.text+0xe): undefined reference to `readline'
collect2: error: ld returned 1 exit status

The same code compiles perfect on my notebook Ubuntu 10.04.

also tryed:

cc -L/usr/lib/x86_64-linux-gnu  -lreadline read_test.c

or

cc -L/usr/lib/x86_64-linux-gnu  -lreadline -lncurses read_test.c

and several other variants with -m64 or --static

I have installed libreadline6-dev and libreadline5-dev.

Thanks in advance.

LALO

Answer 1

Put your arguments for the linker after instead of before your other arguments to gcc:

ek@Ilex:~/source$ gcc -lreadline read_test.c
/tmp/cc1IuVNQ.o: In function `main':
read_test.c:(.text+0xe): undefined reference to `readline'
collect2: error: ld returned 1 exit status
ek@Ilex:~/source$ gcc read_test.c -lreadline
ek@Ilex:~/source$ ./a.out
enter text>foo
text: foo ^C