/*
* The kernel extpread includes a flags argument that allows the blocking
* and append mode(s) to be overridden.
*/
ssize_t
pread(int fd, void *buf, size_t nbyte, off_t offset)
{
return (extpread(fd, buf, nbyte, 0, offset));
}
/*
* cl_read --
* Read characters from the input.
*/
static input_t
cl_read(SCR *sp, u_int32_t flags, char *bp, size_t blen, int *nrp, struct timeval *tp)
{
struct termios term1, term2;
CL_PRIVATE *clp;
GS *gp;
fd_set rdfd;
input_t rval;
int maxfd, nr, term_reset;
gp = sp->gp;
clp = CLP(sp);
term_reset = 0;
/*
* 1: A read from a file or a pipe. In this case, the reads
* never timeout regardless. This means that we can hang
* when trying to complete a map, but we're going to hang
* on the next read anyway.
*/
if (!F_ISSET(clp, CL_STDIN_TTY)) {
nr = extpread(STDIN_FILENO, bp, blen, O_FBLOCKING, -1);
switch (nr) {
case 0:
return (INP_EOF);
case -1:
goto err;
default:
*nrp = nr;
return (INP_OK);
}
/* NOTREACHED */
}
/*
* 2: A read with an associated timeout, e.g., trying to complete
* a map sequence. If input exists, we fall into #3.
*/
if (tp != NULL) {
FD_ZERO(&rdfd);
FD_SET(STDIN_FILENO, &rdfd);
switch (select(STDIN_FILENO + 1, &rdfd, NULL, NULL, tp)) {
case 0:
return (INP_TIMEOUT);
case -1:
goto err;
default:
break;
}
}
/*
* The user can enter a key in the editor to quote a character. If we
* get here and the next key is supposed to be quoted, do what we can.
* Reset the tty so that the user can enter a ^C, ^Q, ^S. There's an
* obvious race here, when the key has already been entered, but there's
* nothing that we can do to fix that problem.
*
* The editor can ask for the next literal character even thought it's
* generally running in line-at-a-time mode. Do what we can.
*/
if (LF_ISSET(EC_QUOTED | EC_RAW) && !tcgetattr(STDIN_FILENO, &term1)) {
term_reset = 1;
if (LF_ISSET(EC_QUOTED)) {
term2 = term1;
term2.c_lflag &= ~ISIG;
term2.c_iflag &= ~(IXON | IXOFF);
(void)tcsetattr(STDIN_FILENO,
TCSASOFT | TCSADRAIN, &term2);
} else
(void)tcsetattr(STDIN_FILENO,
TCSASOFT | TCSADRAIN, &clp->vi_enter);
}
/*
* 3: Wait for input.
*
* Select on the command input and scripting window file descriptors.
* It's ugly that we wait on scripting file descriptors here, but it's
* the only way to keep from locking out scripting windows.
*/
if (F_ISSET(gp, G_SCRWIN)) {
loop: FD_ZERO(&rdfd);
FD_SET(STDIN_FILENO, &rdfd);
maxfd = STDIN_FILENO;
if (F_ISSET(sp, SC_SCRIPT)) {
FD_SET(sp->script->sh_master, &rdfd);
if (sp->script->sh_master > maxfd)
maxfd = sp->script->sh_master;
}
switch (select(maxfd + 1, &rdfd, NULL, NULL, NULL)) {
case 0:
abort();
case -1:
goto err;
default:
break;
}
if (!FD_ISSET(STDIN_FILENO, &rdfd)) {
if (sscr_input(sp))
return (INP_ERR);
goto loop;
}
}
/*
* 4: Read the input.
*
* !!!
* What's going on here is some scary stuff. Ex runs the terminal in
* canonical mode. So, the <newline> character terminating a line of
* input is returned in the buffer, but a trailing <EOF> character is
* not similarly included. As ex uses 0<EOF> and ^<EOF> as autoindent
* commands, it has to see the trailing <EOF> characters to determine
* the difference between the user entering "0ab" and "0<EOF>ab". We
* leave an extra slot in the buffer, so that we can add a trailing
* <EOF> character if the buffer isn't terminated by a <newline>. We
* lose if the buffer is too small for the line and exactly N characters
* are entered followed by an <EOF> character.
*/
#define ONE_FOR_EOF 1
nr = extpread(STDIN_FILENO, bp, blen - ONE_FOR_EOF, O_FBLOCKING, -1);
switch (nr) {
case 0: /* EOF. */
/*
* ^D in canonical mode returns a read of 0, i.e. EOF. EOF is
* a valid command, but we don't want to loop forever because
* the terminal driver is returning EOF because the user has
* disconnected. The editor will almost certainly try to write
* something before this fires, which should kill us, but You
* Never Know.
*/
if (++clp->eof_count < 50) {
bp[0] = clp->orig.c_cc[VEOF];
*nrp = 1;
rval = INP_OK;
} else
rval = INP_EOF;
break;
case -1: /* Error or interrupt. */
err: if (errno == EINTR)
rval = INP_INTR;
else {
rval = INP_ERR;
msgq(sp, M_SYSERR, "input");
}
break;
default: /* Input characters. */
if (F_ISSET(sp, SC_EX) && bp[nr - 1] != '\n')
bp[nr++] = clp->orig.c_cc[VEOF];
*nrp = nr;
clp->eof_count = 0;
rval = INP_OK;
break;
}
/* Restore the terminal state if it was modified. */
if (term_reset)
(void)tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &term1);
return (rval);
}