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/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2011 AT&T Intellectual Property *
* and is licensed under the *
* Eclipse Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.eclipse.org/org/documents/epl-v10.html *
* (with md5 checksum b35adb5213ca9657e911e9befb180842) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Research
*
* return 1 if path exisis
* maintains a cache to minimize stat(2) calls
* path is modified in-place but restored on return
* path components checked in pairs to cut stat()'s
* in half by checking ENOTDIR vs. ENOENT
* case ignorance infection unavoidable here
*/
#include "lclib.h"
#include <ls.h>
#include <error.h>
typedef struct Tree_s
{
struct Tree_s* next;
struct Tree_s* tree;
int mode;
char name[1];
} Tree_t;
int
pathexists(char* path, int mode)
{
register char* s;
register char* e;
register Tree_t* p;
register Tree_t* t;
register int c;
char* ee;
int cc;
int x;
struct stat st;
int (*cmp)(const char*, const char*);
static Tree_t tree;
t = &tree;
e = (c = *path) == '/' ? path + 1 : path;
cmp = strchr(astconf("PATH_ATTRIBUTES", path, NiL), 'c') ? strcasecmp : strcmp;
if ((ast.locale.set & (AST_LC_debug|AST_LC_find)) == (AST_LC_debug|AST_LC_find))
sfprintf(sfstderr, "locale test %s\n", path);
while (c)
{
p = t;
for (s = e; *e && *e != '/'; e++);
c = *e;
*e = 0;
for (t = p->tree; t && (*cmp)(s, t->name); t = t->next);
if (!t)
{
if (!(t = newof(0, Tree_t, 1, strlen(s))))
{
*e = c;
return 0;
}
strcpy(t->name, s);
t->next = p->tree;
p->tree = t;
if (c)
{
*e = c;
for (s = ee = e + 1; *ee && *ee != '/'; ee++);
cc = *ee;
*ee = 0;
}
else
ee = 0;
if ((ast.locale.set & (AST_LC_debug|AST_LC_find)) == (AST_LC_debug|AST_LC_find))
sfprintf(sfstderr, "locale stat %s\n", path);
x = stat(path, &st);
if (ee)
{
e = ee;
c = cc;
if (!x || errno == ENOENT)
t->mode = PATH_READ|PATH_EXECUTE;
if (!(p = newof(0, Tree_t, 1, strlen(s))))
{
*e = c;
return 0;
}
strcpy(p->name, s);
p->next = t->tree;
t->tree = p;
t = p;
}
if (x)
{
*e = c;
return 0;
}
if (st.st_mode & (S_IRUSR|S_IRGRP|S_IROTH))
t->mode |= PATH_READ;
if (st.st_mode & (S_IWUSR|S_IWGRP|S_IWOTH))
t->mode |= PATH_WRITE;
if (st.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH))
t->mode |= PATH_EXECUTE;
if (!S_ISDIR(st.st_mode))
t->mode |= PATH_REGULAR;
}
*e++ = c;
if (!t->mode || c && (t->mode & PATH_REGULAR))
return 0;
}
mode &= (PATH_READ|PATH_WRITE|PATH_EXECUTE|PATH_REGULAR);
return (t->mode & mode) == mode;
}
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