/*********************************************************************** * * * This software is part of the ast package * * Copyright (c) 1985-2010 AT&T Intellectual Property * * and is licensed under the * * Common Public License, Version 1.0 * * by AT&T Intellectual Property * * * * A copy of the License is available at * * http://www.opensource.org/licenses/cpl1.0.txt * * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * * * * Information and Software Systems Research * * AT&T Research * * Florham Park NJ * * * * Glenn Fowler * * David Korn * * Phong Vo * * * ***********************************************************************/ #pragma prototyped /* * K. P. Vo * G. S. Fowler * AT&T Research */ #include #include #include #if DEBUG #undef PATH_MAX #define PATH_MAX 16 static int vchdir(const char* path) { int n; if (strlen(path) >= PATH_MAX) { errno = ENAMETOOLONG; n = -1; } else n = chdir(path); return n; } #define chdir(p) vchdir(p) #endif /* * set the current directory to path * if path is long and home!=0 then pathcd(home,0) * is called on intermediate chdir errors */ int pathcd(const char* path, const char* home) { register char* p = (char*)path; register char* s; register int n; int i; int r; r = 0; for (;;) { /* * this should work 99% of the time */ if (!chdir(p)) return r; /* * chdir failed */ if ((n = strlen(p)) < PATH_MAX) return -1; #ifdef ENAMETOOLONG if (errno != ENAMETOOLONG) return -1; #endif /* * path is too long -- copy so it can be modified in place */ i = stktell(stkstd); sfputr(stkstd, p, 0); stkseek(stkstd, i); p = stkptr(stkstd, i); for (;;) { /* * get a short prefix component */ s = p + PATH_MAX; while (--s >= p && *s != '/'); if (s <= p) break; /* * chdir to the prefix */ *s++ = 0; if (chdir(p)) break; /* * do the remainder */ if ((n -= s - p) < PATH_MAX) { if (chdir(s)) break; return r; } p = s; } /* * try to recover back to home */ if (!(p = (char*)home)) return -1; home = 0; r = -1; } }