#include <stdio.h>
int main(int argc, char * argv[]) {
    char buf[256];
    if(argc == 1) {
        printf("Usage: %s inputn", argv[0]);
        exit(0);
    }
    strcpy(buf,argv[1]);
    printf("%s", buf);
}

Breakpoint 1, 0x080497d6 in main ()
(gdb) info registers
eax            0xbffff1f0   -1073745424
ecx            0xbffff575   -1073744523
edx            0xbffff1f0   -1073745424
ebx            0x80da000    135110656
esp            0xbffff1e0   0xbffff1e0
ebp            0xbffff2f8   0xbffff2f8
esi            0x80da000    135110656
edi            0x80481e8    134513128
eip            0x80497d6    0x80497d6 <main+97>
eflags         0x246    [ PF ZF IF ]
cs             0x73 115
ss             0x7b 123
ds             0x7b 123
es             0x7b 123
fs             0x0  0
gs             0x33 51