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(xgetcwd): If the required pathname length is smaller

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than 1024, return a memory chunk of least possible size, instead
of size PATH_MAX + 2. In the loop, increment the size proportionally.
Use free/xmalloc instead of xrealloc to avoid copying for very long paths.
This commit is contained in:
Jim Meyering 2000-06-21 20:16:03 +00:00
parent 0c3c6ef55e
commit 978bf5f750
1 changed files with 27 additions and 21 deletions
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48
lib/xgetcwd.c
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@ -1,5 +1,5 @@
/* xgetcwd.c -- return current directory with unlimited length
Copyright (C) 1992, 1996 Free Software Foundation, Inc.
Copyright (C) 1992, 1996, 2000 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@ -37,12 +37,9 @@ char *getwd ();
# define getcwd(Buf, Max) getwd (Buf)
#endif
/* Amount to increase buffer size by in each try. */
#define PATH_INCR 32
char *xmalloc ();
char *xrealloc ();
void free ();
extern void *xmalloc ();
extern char *xstrdup ();
extern void free ();
/* Return the current directory, newly allocated, arbitrarily long.
Return NULL and set errno on error. */
@ -50,30 +47,39 @@ void free ();
char *
xgetcwd ()
{
char *cwd;
char *ret;
unsigned path_max;
char buf[1024];
errno = 0;
ret = getcwd (buf, sizeof (buf));
if (ret != NULL)
return xstrdup (buf);
if (errno != ERANGE)
return NULL;
path_max = (unsigned) PATH_MAX;
path_max += 2; /* The getcwd docs say to do this. */
cwd = xmalloc (path_max);
errno = 0;
while ((ret = getcwd (cwd, path_max)) == NULL && errno == ERANGE)
for (;;)
{
path_max += PATH_INCR;
cwd = xrealloc (cwd, path_max);
char *cwd = (char *) xmalloc (path_max);
errno = 0;
}
ret = getcwd (cwd, path_max);
if (ret != NULL)
return ret;
if (errno != ERANGE)
{
int save_errno = errno;
free (cwd);
errno = save_errno;
return NULL;
}
if (ret == NULL)
{
int save_errno = errno;
free (cwd);
errno = save_errno;
return NULL;
path_max += path_max / 16;
path_max += 32;
}
return cwd;
}