ref: d4124d48f9c7e85fdaa50640035080174c94196e
dir: /sys/src/ape/cmd/pax/ttyio.c/
/* $Source: /u/mark/src/pax/RCS/ttyio.c,v $
*
* $Revision: 1.2 $
*
* ttyio.c - Terminal/Console I/O functions for all archive interfaces
*
* DESCRIPTION
*
* These routines provide a consistent, general purpose interface to
* the user via the users terminal, if it is available to the
* process.
*
* AUTHOR
*
* Mark H. Colburn, NAPS International (mark@jhereg.mn.org)
*
* Sponsored by The USENIX Association for public distribution.
*
* Copyright (c) 1989 Mark H. Colburn.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice is duplicated in all such
* forms and that any documentation, advertising materials, and other
* materials related to such distribution and use acknowledge that the
* software was developed * by Mark H. Colburn and sponsored by The
* USENIX Association.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* $Log: ttyio.c,v $
* Revision 1.2 89/02/12 10:06:11 mark
* 1.2 release fixes
*
* Revision 1.1 88/12/23 18:02:39 mark
* Initial revision
*
*/
#ifndef lint
static char *ident = "$Id: ttyio.c,v 1.2 89/02/12 10:06:11 mark Exp $";
static char *copyright = "Copyright (c) 1989 Mark H. Colburn.\nAll rights reserved.\n";
#endif /* ! lint */
/* Headers */
#include "pax.h"
/* open_tty - open the terminal for interactive queries
*
* DESCRIPTION
*
* Assumes that background processes ignore interrupts and that the
* open() or the isatty() will fail for processes which are not
* attached to terminals. Returns a file descriptor or -1 if
* unsuccessful.
*
* RETURNS
*
* Returns a file descriptor which can be used to read and write
* directly to the user's terminal, or -1 on failure.
*
* ERRORS
*
* If SIGINT cannot be ignored, or the open fails, or the newly opened
* terminal device is not a tty, then open_tty will return a -1 to the
* caller.
*/
#ifdef __STDC__
int open_tty(void)
#else
int open_tty()
#endif
{
int fd; /* file descriptor for terminal */
SIG_T (*intr)(); /* used to restore interupts if signal fails */
if ((intr = signal(SIGINT, SIG_IGN)) == SIG_IGN) {
return (-1);
}
signal(SIGINT, intr);
if ((fd = open(TTY, O_RDWR)) < 0) {
return (-1);
}
if (isatty(fd)) {
return (fd);
}
close(fd);
return (-1);
}
/* nextask - ask a question and get a response
*
* DESCRIPTION
*
* Give the user a prompt and wait for their response. The prompt,
* located in "msg" is printed, then the user is allowed to type
* a response to the message. The first "limit" characters of the
* user response is stored in "answer".
*
* Nextask ignores spaces and tabs.
*
* PARAMETERS
*
* char *msg - Message to display for user
* char *answer - Pointer to user's response to question
* int limit - Limit of length for user's response
*
* RETURNS
*
* Returns the number of characters in the user response to the
* calling function. If an EOF was encountered, a -1 is returned to
* the calling function. If an error occured which causes the read
* to return with a value of -1, then the function will return a
* non-zero return status to the calling process, and abort
* execution.
*/
#ifdef __STDC__
int nextask(char *msg, char *answer, int limit)
#else
int nextask(msg, answer, limit)
char *msg; /* message to display for user */
char *answer; /* pointer to user's response to question */
int limit; /* limit of length for user's response */
#endif
{
int idx; /* index into answer for character input */
int got; /* number of characters read */
char c; /* character read */
if (ttyf < 0) {
fatal("/dev/tty Unavailable");
}
write(ttyf, msg, (uint) strlen(msg));
idx = 0;
while ((got = read(ttyf, &c, 1)) == 1) {
if (c == '\n') {
break;
} else if (c == ' ' || c == '\t') {
continue;
} else if (idx < limit - 1) {
answer[idx++] = c;
}
}
if (got == 0) { /* got an EOF */
return(-1);
}
if (got < 0) {
fatal(strerror());
}
answer[idx] = '\0';
return(0);
}
/* lineget - get a line from a given stream
*
* DESCRIPTION
*
* Get a line of input for the stream named by "stream". The data on
* the stream is put into the buffer "buf".
*
* PARAMETERS
*
* FILE *stream - Stream to get input from
* char *buf - Buffer to put input into
*
* RETURNS
*
* Returns 0 if successful, -1 at EOF.
*/
#ifdef __STDC__
int lineget(FILE *stream, char *buf)
#else
int lineget(stream, buf)
FILE *stream; /* stream to get input from */
char *buf; /* buffer to put input into */
#endif
{
int c;
for (;;) {
if ((c = getc(stream)) == EOF) {
return (-1);
}
if (c == '\n') {
break;
}
*buf++ = c;
}
*buf = '\0';
return (0);
}
/* next - Advance to the next archive volume.
*
* DESCRIPTION
*
* Prompts the user to replace the backup medium with a new volume
* when the old one is full. There are some cases, such as when
* archiving to a file on a hard disk, that the message can be a
* little surprising. Assumes that background processes ignore
* interrupts and that the open() or the isatty() will fail for
* processes which are not attached to terminals. Returns a file
* descriptor or -1 if unsuccessful.
*
* PARAMETERS
*
* int mode - mode of archive (READ, WRITE, PASS)
*/
#ifdef __STDC__
void next(int mode)
#else
void next(mode)
int mode; /* mode of archive (READ, WRITE, PASS) */
#endif
{
char msg[200]; /* buffer for message display */
char answer[20]; /* buffer for user's answer */
int ret;
close_archive();
sprintf(msg, "%s: Ready for volume %u\n%s: Type \"go\" when ready to proceed (or \"quit\" to abort): \07",
myname, arvolume + 1, myname);
for (;;) {
ret = nextask(msg, answer, sizeof(answer));
if (ret == -1 || strcmp(answer, "quit") == 0) {
fatal("Aborted");
}
if (strcmp(answer, "go") == 0 && open_archive(mode) == 0) {
break;
}
}
warnarch("Continuing", (OFFSET) 0);
}