В каких обстоятельствах getcwd() возвращает NULL?

Question

char cwd[256]; 
if (getcwd(cwd, sizeof(cwd)) == NULL) { 
    return -1; 
} 

Первое приходит на ум, что getcwd() может вернуть NULL, когда cwd недостаточно велик. Есть ли другие случаи?

Answer 1

Its documentation состояния:

ERRORS 

    The getcwd() function shall fail if: 

    [EINVAL] 
     The size argument is 0. 
    [ERANGE] 
     The size argument is greater than 0, but is smaller than the length of the pathname +1. 

    The getcwd() function may fail if: 

    [EACCES] 
     Read or search permission was denied for a component of the pathname. 
    [ENOMEM] 
     Insufficient storage space is available. 

Answer 2

If the length of the absolute pathname of the current working direc‐ 
     tory, including the terminating null byte, exceeds size bytes, NULL is 
     returned, and errno is set to ERANGE; an application should check for 
     this error, and allocate a larger buffer if necessary. 

источник: человек getcwd