dln_find.c
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/**********************************************************************
dln_find.c -
$Author: nobu $
created at: Tue Jan 18 17:05:06 JST 1994
Copyright (C) 1993-2007 Yukihiro Matsumoto
**********************************************************************/
#ifdef RUBY_EXPORT
#include "ruby/ruby.h"
#define dln_notimplement rb_notimplement
#define dln_memerror rb_memerror
#define dln_exit rb_exit
#define dln_loaderror rb_loaderror
#define dln_warning rb_warning
#define dln_warning_arg
#else
#define dln_notimplement --->>> dln not implemented <<<---
#define dln_memerror abort
#define dln_exit exit
#define dln_warning fprintf
#define dln_warning_arg stderr,
static void dln_loaderror(const char *format, ...);
#endif
#include "dln.h"
#ifdef HAVE_STDLIB_H
# include <stdlib.h>
#endif
#ifdef USE_DLN_A_OUT
char *dln_argv0;
#endif
#if defined(HAVE_ALLOCA_H)
#include <alloca.h>
#endif
#ifdef HAVE_STRING_H
# include <string.h>
#else
# include <strings.h>
#endif
#ifndef xmalloc
void *xmalloc();
void *xcalloc();
void *xrealloc();
#endif
#define free(x) xfree(x)
#include <stdio.h>
#if defined(_WIN32)
#include "missing/file.h"
#endif
#include <sys/types.h>
#include <sys/stat.h>
#ifndef S_ISDIR
# define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif
#ifdef HAVE_SYS_PARAM_H
# include <sys/param.h>
#endif
#ifndef MAXPATHLEN
# define MAXPATHLEN 1024
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifndef _WIN32
char *getenv();
#endif
static char *dln_find_1(const char *fname, const char *path, char *buf, size_t size, int exe_flag);
char *
dln_find_exe_r(const char *fname, const char *path, char *buf, size_t size)
{
char *envpath = 0;
if (!path) {
path = getenv(PATH_ENV);
if (path) path = envpath = strdup(path);
}
if (!path) {
#if defined(_WIN32)
path = "/usr/local/bin;/usr/ucb;/usr/bin;/bin;.";
#else
path = "/usr/local/bin:/usr/ucb:/usr/bin:/bin:.";
#endif
}
buf = dln_find_1(fname, path, buf, size, 1);
if (envpath) free(envpath);
return buf;
}
char *
dln_find_file_r(const char *fname, const char *path, char *buf, size_t size)
{
if (!path) path = ".";
return dln_find_1(fname, path, buf, size, 0);
}
static char fbuf[MAXPATHLEN];
char *
dln_find_exe(const char *fname, const char *path)
{
return dln_find_exe_r(fname, path, fbuf, sizeof(fbuf));
}
char *
dln_find_file(const char *fname, const char *path)
{
return dln_find_file_r(fname, path, fbuf, sizeof(fbuf));
}
static char *
dln_find_1(const char *fname, const char *path, char *fbuf, size_t size,
int exe_flag /* non 0 if looking for executable. */)
{
register const char *dp;
register const char *ep;
register char *bp;
struct stat st;
size_t i, fnlen, fspace;
#ifdef DOSISH
static const char extension[][5] = {
EXECUTABLE_EXTS,
};
size_t j;
int is_abs = 0, has_path = 0;
const char *ext = 0;
#endif
const char *p = fname;
static const char pathname_too_long[] = "openpath: pathname too long (ignored)\n\
\tDirectory \"%.*s\"%s\n\tFile \"%.*s\"%s\n";
#define PATHNAME_TOO_LONG() dln_warning(dln_warning_arg pathname_too_long, \
((bp - fbuf) > 100 ? 100 : (int)(bp - fbuf)), fbuf, \
((bp - fbuf) > 100 ? "..." : ""), \
(fnlen > 100 ? 100 : (int)fnlen), fname, \
(fnlen > 100 ? "..." : ""))
#define RETURN_IF(expr) if (expr) return (char *)fname;
RETURN_IF(!fname);
fnlen = strlen(fname);
if (fnlen >= size) {
dln_warning(dln_warning_arg
"openpath: pathname too long (ignored)\n\tFile \"%.*s\"%s\n",
(fnlen > 100 ? 100 : (int)fnlen), fname,
(fnlen > 100 ? "..." : ""));
return NULL;
}
#ifdef DOSISH
# ifndef CharNext
# define CharNext(p) ((p)+1)
# endif
# ifdef DOSISH_DRIVE_LETTER
if (((p[0] | 0x20) - 'a') < 26 && p[1] == ':') {
p += 2;
is_abs = 1;
}
# endif
switch (*p) {
case '/': case '\\':
is_abs = 1;
p++;
}
has_path = is_abs;
while (*p) {
switch (*p) {
case '/': case '\\':
has_path = 1;
ext = 0;
p++;
break;
case '.':
ext = p;
p++;
break;
default:
p = CharNext(p);
}
}
if (ext) {
for (j = 0; STRCASECMP(ext, extension[j]); ) {
if (++j == sizeof(extension) / sizeof(extension[0])) {
ext = 0;
break;
}
}
}
ep = bp = 0;
if (!exe_flag) {
RETURN_IF(is_abs);
}
else if (has_path) {
RETURN_IF(ext);
i = p - fname;
if (i + 1 > size) goto toolong;
fspace = size - i - 1;
bp = fbuf;
ep = p;
memcpy(fbuf, fname, i + 1);
goto needs_extension;
}
p = fname;
#endif
if (*p == '.' && *++p == '.') ++p;
RETURN_IF(*p == '/');
RETURN_IF(exe_flag && strchr(fname, '/'));
#undef RETURN_IF
for (dp = path;; dp = ++ep) {
register size_t l;
/* extract a component */
ep = strchr(dp, PATH_SEP[0]);
if (ep == NULL)
ep = dp+strlen(dp);
/* find the length of that component */
l = ep - dp;
bp = fbuf;
fspace = size - 2;
if (l > 0) {
/*
** If the length of the component is zero length,
** start from the current directory. If the
** component begins with "~", start from the
** user's $HOME environment variable. Otherwise
** take the path literally.
*/
if (*dp == '~' && (l == 1 ||
#if defined(DOSISH)
dp[1] == '\\' ||
#endif
dp[1] == '/')) {
char *home;
home = getenv("HOME");
if (home != NULL) {
i = strlen(home);
if (fspace < i)
goto toolong;
fspace -= i;
memcpy(bp, home, i);
bp += i;
}
dp++;
l--;
}
if (l > 0) {
if (fspace < l)
goto toolong;
fspace -= l;
memcpy(bp, dp, l);
bp += l;
}
/* add a "/" between directory and filename */
if (ep[-1] != '/')
*bp++ = '/';
}
/* now append the file name */
i = fnlen;
if (fspace < i) {
toolong:
PATHNAME_TOO_LONG();
goto next;
}
fspace -= i;
memcpy(bp, fname, i + 1);
#if defined(DOSISH)
if (exe_flag && !ext) {
needs_extension:
for (j = 0; j < sizeof(extension) / sizeof(extension[0]); j++) {
if (fspace < strlen(extension[j])) {
PATHNAME_TOO_LONG();
continue;
}
strlcpy(bp + i, extension[j], fspace);
if (stat(fbuf, &st) == 0)
return fbuf;
}
goto next;
}
#endif /* _WIN32 or __EMX__ */
if (stat(fbuf, &st) == 0) {
if (exe_flag == 0) return fbuf;
/* looking for executable */
if (!S_ISDIR(st.st_mode) && eaccess(fbuf, X_OK) == 0)
return fbuf;
}
next:
/* if not, and no other alternatives, life is bleak */
if (*ep == '\0') {
return NULL;
}
/* otherwise try the next component in the search path */
}
}