c - printf is causing a segfault with getlogin() -

i'm new c, apologize if answer obvious, i've searched elsewhere.

the libraries i'm including are:

#include <unistd.h> #include <stdio.h> #include <string.h> #include <stdlib.h> #include <sys/wait.h>  #include <fcntl.h> #include <sys/stat.h> 

the code failing is:

    char *user = getlogin();     char cwd[128];      if (user == null)         printf("cry\n");      getcwd(cwd, sizeof(cwd));     printf("this prints\n");     printf(user);     printf("this not\n");     printf("%s@myshell:%s> ", user, cwd); 

cry not print, should mean getlogin successful. segfault caused on printf(user);

further testing shows folling block prints entirely

    printf("this prints\n");     printf(user);     printf("this prints\n"); 

but folling block print prints end segfault without showing user

    printf("this prints\n");     printf(user); 

edit:

sorry wasting time. accidentally deleted fgets supposed follow , causing segfault. i've been on bug couple hours now, love when problem small.

thanks

you should check getcwd return value. according man page of getcwd:

if length of absolute pathname of current working directory, including terminating null byte, exceeds size bytes, null returned, , errno set erange; application should check error, , allocate larger buffer if necessary.