BSD 4_3_Net_2 release

[unix-history] / usr / src / lib / libc / gen / getpass.c

/*
* Copyright (c) 1988 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getpass.c   5.9 (Berkeley) 5/6/91";
#endif /* LIBC_SCCS and not lint */

#include <sys/termios.h>
#include <sys/signal.h>
#include <stdio.h>
#include <unistd.h>
#include <pwd.h>

char *
getpass(prompt)
       const char *prompt;
{
       struct termios term;
       register int ch;
       register char *p;
       FILE *fp, *outfp;
       long omask;
       int echo;
       static char buf[_PASSWORD_LEN + 1];

       /*
        * read and write to /dev/tty if possible; else read from
        * stdin and write to stderr.
        */
       if ((outfp = fp = fopen("/dev/tty", "w+")) == NULL) {
               outfp = stderr;
               fp = stdin;
       }
       /*
        * note - blocking signals isn't necessarily the
        * right thing, but we leave it for now.
        */
       omask = sigblock(sigmask(SIGINT)|sigmask(SIGTSTP));
       (void)tcgetattr(fileno(fp), &term);
       if (echo = (term.c_lflag & ECHO)) {
               term.c_lflag &= ~ECHO;
               (void)tcsetattr(fileno(fp), TCSAFLUSH|TCSASOFT, &term);
       }
       (void)fputs(prompt, outfp);
       rewind(outfp);                  /* implied flush */
       for (p = buf; (ch = getc(fp)) != EOF && ch != '\n';)
               if (p < buf + _PASSWORD_LEN)
                       *p++ = ch;
       *p = '\0';
       (void)write(fileno(outfp), "\n", 1);
       if (echo) {
               term.c_lflag |= ECHO;
               tcsetattr(fileno(fp), TCSAFLUSH|TCSASOFT, &term);
       }
       (void)sigsetmask(omask);
       if (fp != stdin)
               (void)fclose(fp);
       return(buf);
}