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oldlinux-files/gnu/glibc/glibc-1.05.tar/glibc-1.05/sysdeps/posix/sysd-stdio.c
2024-02-19 00:24:47 -05:00

298 lines
7.2 KiB
C

/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
/* Read N bytes into BUF from COOKIE. */
int
DEFUN(__stdio_read, (cookie, buf, n),
PTR cookie AND register char *buf AND register size_t n)
{
#if defined (EINTR) && defined (EINTR_REPEAT)
CONST int fd = *(int *) cookie;
int save = errno;
int nread;
try:;
errno = 0;
nread = __read(fd, buf, (int) n);
if (nread < 0)
{
if (errno == EINTR)
goto try;
return -1;
}
errno = save;
return nread;
#else /* No EINTR. */
return __read(*(int *) cookie, buf, (int) n);
#endif
}
/* Write N bytes from BUF to COOKIE. */
int
DEFUN(__stdio_write, (cookie, buf, n),
PTR cookie AND register CONST char *buf AND register size_t n)
{
CONST int fd = *(int *) cookie;
register size_t written = 0;
while (n > 0)
{
int count = __write (fd, buf, (int) n);
if (count > 0)
{
buf += count;
written += count;
n -= count;
}
else if (count < 0
#if defined (EINTR) && defined (EINTR_REPEAT)
&& errno != EINTR
#endif
)
/* Write error. */
return -1;
}
return (int) written;
}
/* Move COOKIE's file position *POS bytes, according to WHENCE.
The new file position is stored in *POS.
Returns zero if successful, nonzero if not. */
int
DEFUN(__stdio_seek, (cookie, pos, whence),
PTR cookie AND fpos_t *pos AND int whence)
{
off_t new;
new = __lseek(*(int *) cookie, (off_t) *pos, whence);
if (new < 0)
return 1;
*pos = (fpos_t) new;
return 0;
}
/* Close COOKIE. */
int
DEFUN(__stdio_close, (cookie), PTR cookie)
{
return __close(*(int *) cookie);
}
/* Open the given file with the mode given in the __io_mode argument. */
PTR
DEFUN(__stdio_open, (filename, m, fdptr),
CONST char *filename AND __io_mode m AND int *fdptr)
{
int mode;
if (m.__read && m.__write)
mode = O_RDWR;
else
mode = m.__read ? O_RDONLY : O_WRONLY;
if (m.__append)
mode |= O_APPEND;
if (m.__exclusive)
mode |= O_EXCL;
if (m.__truncate)
mode |= O_TRUNC;
if (m.__create)
*fdptr = __open(filename, mode | O_CREAT,
S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
else
*fdptr = __open(filename, mode);
return NULL;
}
/* Write a message to the error output.
Try hard to make it really get out. */
void
DEFUN(__stdio_errmsg, (msg, len), CONST char *msg AND size_t len)
{
while (len > 0)
{
register int count = __write(2, msg, (int) len);
if (count > 0)
{
msg += count;
len -= count;
}
else if (count < 0
#if defined (EINTR) && defined (EINTR_REPEAT)
&& errno != EINTR
#endif
)
break;
}
}
/* Return nonzero if DIR is an existent directory. */
static int
DEFUN(diraccess, (dir), CONST char *dir)
{
struct stat buf;
return __stat (dir, &buf) == 0 && S_ISDIR (buf.st_mode);
}
/* Return nonzero if FILE exists. */
static int
DEFUN(exists, (file), CONST char *file)
{
/* We can stat the file even if we can't read its data. */
struct stat st;
return __stat (file, &st) == 0;
}
/* These are the characters used in temporary filenames. */
static CONST char letters[] =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
/* Generate a temporary filename.
If DIR_SEARCH is nonzero, DIR and PFX are used as
described for tempnam. If not, a temporary filename
in P_tmpdir with no special prefix is generated. If LENPTR
is not NULL, *LENPTR is set the to length (including the
terminating '\0') of the resultant filename, which is returned.
This goes through a cyclic pattern of all possible filenames
consisting of five decimal digits of the current pid and three
of the characters in `letters'. Data for tempnam and tmpnam
is kept separate, but when tempnam is using P_tmpdir and no
prefix (i.e, it is identical to tmpnam), the same data is used.
Each potential filename is tested for an already-existing file of
the same name, and no name of an existing file will be returned.
When the cycle reaches its end (12345ZZZ), NULL is returned. */
char *
DEFUN(__stdio_gen_tempname, (dir, pfx, dir_search, lenptr),
CONST char *dir AND CONST char *pfx AND
int dir_search AND size_t *lenptr)
{
static CONST char tmpdir[] = P_tmpdir;
static struct
{
char buf[3];
char *s;
size_t i;
} infos[2], *info;
static char buf[FILENAME_MAX];
static pid_t oldpid = (pid_t) 0;
pid_t pid = __getpid();
register size_t len, plen, dlen;
if (dir_search)
{
register CONST char *d = getenv("TMPDIR");
if (d != NULL && !diraccess(d))
d = NULL;
if (d == NULL && dir != NULL && diraccess(dir))
d = dir;
if (d == NULL && diraccess(tmpdir))
d = tmpdir;
if (d == NULL && diraccess("/tmp"))
d = "/tmp";
if (d == NULL)
{
errno = ENOENT;
return NULL;
}
dir = d;
}
else
dir = tmpdir;
dlen = strlen (dir);
/* Remove trailing slashes from the directory name. */
while (dlen > 1 && dir[dlen - 1] == '/')
--dlen;
if (pfx != NULL && *pfx != '\0')
{
plen = strlen(pfx);
if (plen > 5)
plen = 5;
}
else
plen = 0;
if (dir != tmpdir && !strcmp(dir, tmpdir))
dir = tmpdir;
info = &infos[(plen == 0 && dir == tmpdir) ? 1 : 0];
if (pid != oldpid)
{
oldpid = pid;
infos[0].buf[0] = infos[0].buf[1] = infos[0].buf[2] = letters[0];
infos[0].s = infos[0].buf;
infos[0].i = 0;
infos[1].buf[0] = infos[1].buf[1] = infos[1].buf[2] = letters[0];
infos[1].s = infos[1].buf;
infos[1].i = 0;
}
len = dlen + 1 + plen + 8;
for (;;)
{
*info->s = letters[info->i];
if (sprintf(buf, "%.*s/%.*s%.5d%.3s", (int) dlen, dir, (int) plen,
pfx, pid % 100000, info->buf) != (int) len)
return NULL;
/* Always return a unique string. */
++info->i;
if (!exists (buf))
break;
if (info->i > sizeof (letters) - 2)
{
info->i = 0;
if (info->s == &info->buf[2])
{
errno = EEXIST;
return NULL;
}
++info->s;
}
}
if (lenptr != NULL)
*lenptr = len + 1;
return buf;
}