openssh/tildexpand.c

72 lines
2.0 KiB
C

/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
#include "includes.h"
RCSID("$OpenBSD: tildexpand.c,v 1.10 2001/01/21 19:06:01 markus Exp $");
#include "xmalloc.h"
#include "log.h"
/*
* Expands tildes in the file name. Returns data allocated by xmalloc.
* Warning: this calls getpw*.
*/
char *
tilde_expand_filename(const char *filename, uid_t my_uid)
{
const char *cp;
u_int userlen;
char *expanded;
struct passwd *pw;
char user[100];
int len;
/* Return immediately if no tilde. */
if (filename[0] != '~')
return xstrdup(filename);
/* Skip the tilde. */
filename++;
/* Find where the username ends. */
cp = strchr(filename, '/');
if (cp)
userlen = cp - filename; /* Something after username. */
else
userlen = strlen(filename); /* Nothing after username. */
if (userlen == 0)
pw = getpwuid(my_uid); /* Own home directory. */
else {
/* Tilde refers to someone elses home directory. */
if (userlen > sizeof(user) - 1)
fatal("User name after tilde too long.");
memcpy(user, filename, userlen);
user[userlen] = 0;
pw = getpwnam(user);
}
if (!pw)
fatal("Unknown user %100s.", user);
/* If referring to someones home directory, return it now. */
if (!cp) {
/* Only home directory specified */
return xstrdup(pw->pw_dir);
}
/* Build a path combining the specified directory and path. */
len = strlen(pw->pw_dir) + strlen(cp + 1) + 2;
if (len > MAXPATHLEN)
fatal("Home directory too long (%d > %d", len-1, MAXPATHLEN-1);
expanded = xmalloc(len);
snprintf(expanded, len, "%s/%s", pw->pw_dir, cp + 1);
return expanded;
}