pathpath.c revision 34f9b3eef6fdadbda0a846aa4d68691ac40eace5
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2009 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 <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Research
*
* return full path to p with mode access using $PATH
* a!=0 enables related root search
* a!=0 && a!="" searches a dir first
* the related root must have a bin subdir
* p==0 sets the cached relative dir to a
* full path returned in path buffer
* if path==0 then the space is malloc'd
*/
#include <ast.h>
char*
pathpath(register char* path, const char* p, const char* a, int mode)
{
register char* s;
char* x;
char buf[PATH_MAX];
static char* cmd;
if (!path)
path = buf;
if (!p)
{
if (cmd)
free(cmd);
cmd = a ? strdup(a) : (char*)0;
return 0;
}
if (strlen(p) < PATH_MAX)
{
strcpy(path, p);
if (pathexists(path, mode))
{
if (*p != '/' && (mode & PATH_ABSOLUTE))
{
getcwd(buf, sizeof(buf));
s = buf + strlen(buf);
sfsprintf(s, sizeof(buf) - (s - buf), "/%s", p);
if (path != buf)
strcpy(path, buf);
}
return (path == buf) ? strdup(path) : path;
}
}
if (*p == '/')
a = 0;
else if (s = (char*)a)
{
x = s;
if (strchr(p, '/'))
{
a = p;
p = "..";
}
else
a = 0;
if ((!cmd || *cmd) && (strchr(s, '/') || (s = cmd)))
{
if (!cmd && *s == '/')
cmd = strdup(s);
if (strlen(s) < (sizeof(buf) - 6))
{
s = strcopy(path, s);
for (;;)
{
do if (s <= path) goto normal; while (*--s == '/');
do if (s <= path) goto normal; while (*--s != '/');
strcpy(s + 1, "bin");
if (pathexists(path, PATH_EXECUTE))
{
if (s = pathaccess(path, path, p, a, mode))
return path == buf ? strdup(s) : s;
goto normal;
}
}
normal: ;
}
}
}
x = !a && strchr(p, '/') ? "" : pathbin();
if (!(s = pathaccess(path, x, p, a, mode)) && !*x && (x = getenv("FPATH")))
s = pathaccess(path, x, p, a, mode);
return (s && path == buf) ? strdup(s) : s;
}