1/* vi: set sw=4 ts=4: */ 2/* 3 * xgetcwd.c -- return current directory with unlimited length 4 * Copyright (C) 1992, 1996 Free Software Foundation, Inc. 5 * Written by David MacKenzie <djm@gnu.ai.mit.edu>. 6 * 7 * Special function for busybox written by Vladimir Oleynik <dzo@simtreas.ru> 8*/ 9 10#include "libbb.h" 11 12/* Amount to increase buffer size by in each try. */ 13#define PATH_INCR 32 14 15/* Return the current directory, newly allocated, arbitrarily long. 16 Return NULL and set errno on error. 17 If argument is not NULL (previous usage allocate memory), call free() 18*/ 19 20char * 21xrealloc_getcwd_or_warn(char *cwd) 22{ 23 char *ret; 24 unsigned path_max; 25 26 path_max = (unsigned) PATH_MAX; 27 path_max += 2; /* The getcwd docs say to do this. */ 28 29 if (cwd == NULL) 30 cwd = xmalloc(path_max); 31 32 while ((ret = getcwd(cwd, path_max)) == NULL && errno == ERANGE) { 33 path_max += PATH_INCR; 34 cwd = xrealloc(cwd, path_max); 35 } 36 37 if (ret == NULL) { 38 free(cwd); 39 bb_perror_msg("getcwd"); 40 return NULL; 41 } 42 43 return cwd; 44} 45