astquery.c revision da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2007 AT&T Knowledge Ventures *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Knowledge Ventures *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* AT&T Research
*
* output printf prompt and read response
* if format==0 then verify that interaction is possible
*
* return:
*
* 0 [1yY+]
* -1 [qQ] or EOF
* 1 otherwise
*
* if (quit&ERROR_PROMPT) then tty forced for IO
* if quit>=0 then [qQ] or EOF calls exit(quit)
*/
#include <ast.h>
#include <error.h>
int
astquery(int quit, const char* format, ...)
{
va_list ap;
register int n;
register int c;
Sfio_t* ip;
Sfio_t* op;
static Sfio_t* rfp;
static Sfio_t* wfp;
va_start(ap, format);
if (!format)
return 0;
if (!rfp)
{
c = errno;
if (isatty(sffileno(sfstdin)))
rfp = sfstdin;
else if (!(rfp = sfopen(NiL, "/dev/tty", "r")))
return -1;
if (isatty(sffileno(sfstderr)))
wfp = sfstderr;
else if (!(wfp = sfopen(NiL, "/dev/tty", "w")))
return -1;
errno = c;
}
if (quit & ERROR_PROMPT)
{
quit &= ~ERROR_PROMPT;
ip = rfp;
op = wfp;
}
else
{
ip = sfstdin;
op = sfstderr;
}
sfsync(sfstdout);
sfvprintf(op, format, ap);
sfsync(op);
for (n = c = sfgetc(ip);; c = sfgetc(ip))
switch (c)
{
case EOF:
n = c;
/*FALLTHROUGH*/
case '\n':
switch (n)
{
case EOF:
case 'q':
case 'Q':
if (quit >= 0)
exit(quit);
return -1;
case '1':
case 'y':
case 'Y':
case '+':
return 0;
}
return 1;
}
va_end(ap);
/*NOTREACHED*/
}