foo.c

#include <stdio.h>
#include <stdlib.h>
 
#include <readline/readline.h>
#include <readline/history.h>
 
int
main(int argc, char** argv)
{
        puts("JL 0.0.1");
        puts("Press C-c to exit\n");
 
        //while (1) {
                char *input = readline("jl> ");
                add_history(input);
                printf("%s\n", input);
                free(input);
                //}
 
        return 0;
}

valgrind-error

$ valgrind ./foo
==1861== Memcheck, a memory error detector
==1861== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==1861== Using Valgrind-3.9.0 and LibVEX; rerun with -h for copyright info
==1861== Command: ./foo
==1861== 
JL 0.0.1
Press C-c to exit

jl> 

==1861== 
==1861== HEAP SUMMARY:
==1861==     in use at exit: 122,013 bytes in 187 blocks
==1861==   total heap usage: 2,664 allocs, 2,477 frees, 254,683 bytes allocated
==1861== 
==1861== LEAK SUMMARY:
==1861==    definitely lost: 0 bytes in 0 blocks
==1861==    indirectly lost: 0 bytes in 0 blocks
==1861==      possibly lost: 0 bytes in 0 blocks
==1861==    still reachable: 122,013 bytes in 187 blocks
==1861==         suppressed: 0 bytes in 0 blocks
==1861== Rerun with --leak-check=full to see details of leaked memory
==1861== 
==1861== For counts of detected and suppressed errors, rerun with: -v
==1861== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 2 from 2)