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(tty_name): New function. (login): Use it. (PATH_MAX): MACRO removed. <stdlib.h>: New include.

This commit is contained in:
Miles Bader 1996-06-07 20:32:20 +00:00
parent 64a921419d
commit 500590c767
1 changed files with 63 additions and 8 deletions
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71
login/login.c
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@ -21,27 +21,79 @@ Boston, MA 02111-1307, USA. */
#include <limits.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <utmp.h>
/* Return the result of ttyname in the buffer pointed to by TTY, which should
be of length BUF_LEN. If it is too long to fit in this buffer, a
sufficiently long buffer is allocated using malloc, and returned in TTY.
0 is returned upon success, -1 otherwise. */
static int
tty_name (int fd, char **tty, size_t buf_len)
{
int rv; /* Return value. 0 = success. */
char *buf = *tty; /* Buffer for ttyname, initially the user's. */
/* XXX used for tty name array in login. */
#ifndef PATH_MAX
#define PATH_MAX 1024
#endif
for (;;)
{
char *new_buf;
if (buf_len)
{
rv = ttyname_r (fd, buf, buf_len);
if (rv < 0 || memchr (buf, '\0', buf_len))
/* We either got an error, or we succeeded and the returned name fit
in the buffer. */
break;
/* Try again with a longer buffer. */
buf_len += buf_len; /* Double it */
}
else
/* No initial buffer; start out by mallocing one. */
buf_len = 128; /* First time guess. */
if (buf != *tty)
/* We've already malloced another buffer at least once. */
new_buf = realloc (buf, buf_len);
else
new_buf = malloc (buf_len);
if (! new_buf)
{
rv = -1;
errno = ENOMEM;
break;
}
}
if (rv == 0)
*tty = buf; /* Return buffer to the user. */
else if (buf != *tty)
free (buf); /* Free what we malloced when returning an error. */
return rv;
}
void
login (const struct utmp *ut)
{
char tty[PATH_MAX + UT_LINESIZE];
#ifdef PATH_MAX
char _tty[PATH_MAX + UT_LINESIZE];
#else
char _tty[512 + UT_LINESIZE];
#endif
char *tty = _tty;
int found_tty;
const char *ttyp;
struct utmp_data data;
/* Seek tty. */
found_tty = ttyname_r (STDIN_FILENO, tty, sizeof tty);
found_tty = tty_name (STDIN_FILENO, &tty, sizeof (_tty));
if (found_tty < 0)
found_tty = ttyname_r (STDOUT_FILENO, tty, sizeof tty);
found_tty = tty_name (STDOUT_FILENO, &tty, sizeof (_tty));
if (found_tty < 0)
found_tty = ttyname_r (STDERR_FILENO, tty, sizeof tty);
found_tty = tty_name (STDERR_FILENO, &tty, sizeof (_tty));
if (found_tty >= 0)
{
@ -78,6 +130,9 @@ login (const struct utmp *ut)
/* Close UTMP file. */
endutent_r (&data);
}
if (tty != _tty)
free (tty); /* Free buffer malloced by tty_name. */
}
/* Update the WTMP file. Here we have to add a new entry. */