in erts/etc/unix/to_erl.c [126:489]
int main(int argc, char **argv)
{
char FIFO1[FILENAME_MAX], FIFO2[FILENAME_MAX];
int i, len, wfd, rfd;
fd_set readfds;
char buf[BUFSIZ];
char pipename[FILENAME_MAX];
int pipeIx = 1;
int force_lock = 0;
int got_some = 0;
if (argc >= 2 && argv[1][0]=='-') {
switch (argv[1][1]) {
case 'h':
usage(argv[0]);
exit(1);
case 'F':
force_lock = 1;
break;
default:
fprintf(stderr,"Invalid option '%s'\n",argv[1]);
exit(1);
}
pipeIx = 2;
}
#ifdef DEBUG
fprintf(stderr, "%s: pid is : %d\n", argv[0], (int)getpid());
#endif
strn_cpy(pipename, sizeof(pipename),
(argv[pipeIx] ? argv[pipeIx] : PIPE_DIR));
if(*pipename && pipename[strlen(pipename)-1] == '/') {
/* The user wishes us to find a pipe name in the specified */
/* directory */
int highest_pipe_num = 0;
DIR *dirp;
struct dirent *direntp;
dirp = opendir(pipename);
if(!dirp) {
fprintf(stderr, "Can't access pipe directory %s: %s\n", pipename, strerror(errno));
exit(1);
}
/* Check the directory for existing pipes */
while((direntp=readdir(dirp)) != NULL) {
if(strncmp(direntp->d_name,PIPE_STUBNAME,PIPE_STUBLEN)==0) {
int num = atoi(direntp->d_name+PIPE_STUBLEN+1);
if(num > highest_pipe_num)
highest_pipe_num = num;
}
}
closedir(dirp);
strn_catf(pipename, sizeof(pipename), (highest_pipe_num?"%s.%d":"%s"),
PIPE_STUBNAME, highest_pipe_num);
} /* if */
/* read FIFO */
sn_printf(FIFO1,sizeof(FIFO1),"%s.r",pipename);
/* write FIFO */
sn_printf(FIFO2,sizeof(FIFO2),"%s.w",pipename);
/* Check that nobody is running to_erl on this pipe already */
if ((wfd = open (FIFO1, O_WRONLY|DONT_BLOCK_PLEASE, 0)) >= 0) {
/* Open as server succeeded -- to_erl is already running! */
close(wfd);
fprintf(stderr, "Another to_erl process already attached to pipe "
"%s.\n", pipename);
if (force_lock) {
fprintf(stderr, "But we proceed anyway by force (-F).\n");
}
else {
exit(1);
}
}
if ((rfd = open (FIFO1, O_RDONLY|DONT_BLOCK_PLEASE, 0)) < 0) {
#ifdef DEBUG
fprintf(stderr, "Could not open FIFO %s for reading.\n", FIFO1);
#endif
fprintf(stderr, "No running Erlang on pipe %s: %s\n", pipename, strerror(errno));
exit(1);
}
#ifdef DEBUG
fprintf(stderr, "to_erl: %s opened for reading\n", FIFO1);
#endif
if ((wfd = open (FIFO2, O_WRONLY|DONT_BLOCK_PLEASE, 0)) < 0) {
#ifdef DEBUG
fprintf(stderr, "Could not open FIFO %s for writing.\n", FIFO2);
#endif
fprintf(stderr, "No running Erlang on pipe %s: %s\n", pipename, strerror(errno));
close(rfd);
exit(1);
}
#ifdef DEBUG
fprintf(stderr, "to_erl: %s opened for writing\n", FIFO2);
#endif
fprintf(stderr, "Attaching to %s (^D to exit)\n\n", pipename);
/* Set break handler to our handler */
signal(SIGINT,handle_ctrlc);
/*
* Save the current state of the terminal, and set raw mode.
*/
if (tcgetattr(0, &tty_rmode) , 0) {
fprintf(stderr, "Cannot get terminals current mode\n");
exit(-1);
}
tty_smode = tty_rmode;
tty_eof = '\004'; /* Ctrl+D to exit */
#ifdef DEBUG
show_terminal_settings(&tty_rmode);
#endif
tty_smode.c_iflag =
1*BRKINT |/*Signal interrupt on break.*/
1*IGNPAR |/*Ignore characters with parity errors.*/
0;
#if 0
0*IGNBRK |/*Ignore break condition.*/
0*PARMRK |/*Mark parity errors.*/
0*INPCK |/*Enable input parity check.*/
0*INLCR |/*Map NL to CR on input.*/
0*IGNCR |/*Ignore CR.*/
0*ICRNL |/*Map CR to NL on input.*/
0*IUCLC |/*Map upper-case to lower-case on input.*/
0*IXON |/*Enable start/stop output control.*/
0*IXANY |/*Enable any character to restart output.*/
0*IXOFF |/*Enable start/stop input control.*/
0*IMAXBEL|/*Echo BEL on input line too long.*/
#endif
tty_smode.c_oflag =
OPOST |/*Post-process output.*/
0*ONLCR |/*Map NL to CR-NL on output.*/
#ifdef XTABS
1*XTABS |/*Expand tabs to spaces. (Linux)*/
#endif
#ifdef OXTABS
1*OXTABS |/*Expand tabs to spaces. (FreeBSD)*/
#endif
#ifdef NL0
1*NL0 |/*Select newline delays*/
#endif
#ifdef CR0
1*CR0 |/*Select carriage-return delays*/
#endif
#ifdef TAB0
1*TAB0 |/*Select horizontal tab delays*/
#endif
#ifdef BS0
1*BS0 |/*Select backspace delays*/
#endif
#ifdef VT0
1*VT0 |/*Select vertical tab delays*/
#endif
#ifdef FF0
1*FF0 |/*Select form feed delays*/
#endif
0;
#if 0
0*OLCUC |/*Map lower case to upper on output.*/
0*OCRNL |/*Map CR to NL on output.*/
0*ONOCR |/*No CR output at column 0.*/
0*ONLRET |/*NL performs CR function.*/
0*OFILL |/*Use fill characters for delay.*/
0*OFDEL |/*Fill is DEL, else NULL.*/
0*NL1 |
0*CR1 |
0*CR2 |
0*CR3 |
0*TAB1 |
0*TAB2 |
0*TAB3 |/*Expand tabs to spaces.*/
0*BS1 |
0*VT1 |
0*FF1 |
#endif
/* JALI: removed setting the tty_smode.c_cflag flags, since this is not */
/* advisable if this is a *real* terminal, such as the console. In fact */
/* this may hang the entire machine, deep, deep down (signalling break */
/* or toggling the abort switch doesn't help) */
tty_smode.c_lflag =
0;
#if 0
0*ISIG |/*Enable signals.*/
0*ICANON |/*Canonical input (erase and kill processing).*/
0*XCASE |/*Canonical upper/lower presentation.*/
0*ECHO |/*Enable echo.*/
0*ECHOE |/*Echo erase character as BS-SP-BS.*/
0*ECHOK |/*Echo NL after kill character.*/
0*ECHONL |/*Echo NL.*/
0*NOFLSH |/*Disable flush after interrupt or quit.*/
0*TOSTOP |/*Send SIGTTOU for background output.*/
0*ECHOCTL|/*Echo control characters as ^char, delete as ^?.*/
0*ECHOPRT|/*Echo erase character as character erased.*/
0*ECHOKE |/*BS-SP-BS erase entire line on line kill.*/
0*FLUSHO |/*Output is being flushed.*/
0*PENDIN |/*Retype pending input at next read or input character.*/
0*IEXTEN |/*Enable extended (implementation-defined) functions.*/
#endif
tty_smode.c_cc[VMIN] =0;/* Note that VMIN is the same as VEOF! */
tty_smode.c_cc[VTIME] =0;/* Note that VTIME is the same as VEOL! */
tty_smode.c_cc[VINTR] =3;
tcsetattr(0, TCSADRAIN, &tty_smode);
#ifdef DEBUG
show_terminal_settings(&tty_smode);
#endif
/*
* "Write a ^L to the FIFO which causes the other end to redisplay
* the input line."
* This does not seem to work as was intended in old comment above.
* However, this control character is now (R12B-3) used by run_erl
* to trigger the version handshaking between to_erl and run_erl
* at the start of every new to_erl-session.
*/
if (write(wfd, "\014", 1) < 0) {
fprintf(stderr, "Error in writing ^L to FIFO.\n");
}
/*
* read and write
*/
while (1) {
FD_ZERO(&readfds);
FD_SET(0, &readfds);
FD_SET(rfd, &readfds);
if (select(rfd + 1, &readfds, NULL, NULL, NULL) < 0) {
if (recv_sig) {
FD_ZERO(&readfds);
}
else {
fprintf(stderr, "Error in select.\n");
break;
}
}
len = 0;
/*
* Read from terminal and write to FIFO
*/
if (recv_sig) {
switch (recv_sig) {
case SIGINT:
fprintf(stderr, "[Break]\n\r");
buf[0] = '\003';
len = 1;
break;
case SIGWINCH:
len = window_size_seq(buf,sizeof(buf));
break;
default:
fprintf(stderr,"Unexpected signal: %u\n",recv_sig);
}
recv_sig = 0;
}
else if (FD_ISSET(0, &readfds)) {
len = read(0, buf, sizeof(buf));
if (len <= 0) {
close(rfd);
close(wfd);
if (len < 0) {
fprintf(stderr, "Error in reading from stdin.\n");
} else {
fprintf(stderr, "[EOF]\n\r");
}
break;
}
/* check if there is an eof character in input */
for (i = 0; i < len && buf[i] != tty_eof; i++);
if (buf[i] == tty_eof) {
fprintf(stderr, "[Quit]\n\r");
break;
}
}
if (len) {
#ifdef DEBUG
write_all(1, buf, len);
#endif
if (write_all(wfd, buf, len) != len) {
fprintf(stderr, "Error in writing to FIFO.\n");
close(rfd);
close(wfd);
break;
}
STATUS("\" OK\r\n");
}
/*
* Read from FIFO, write to terminal.
*/
if (FD_ISSET(rfd, &readfds)) {
STATUS("FIFO read: ");
len = read(rfd, buf, BUFSIZ);
if (len < 0 && errno == EAGAIN) {
/*
* No data this time, but the writing end of the FIFO is still open.
* Do nothing.
*/
;
} else if (len <= 0) {
/*
* Either an error or end of file. In either case, break out
* of the loop.
*/
close(rfd);
close(wfd);
if (len < 0) {
fprintf(stderr, "Error in reading from FIFO.\n");
} else
fprintf(stderr, "[End]\n\r");
break;
} else {
if (!got_some) {
if ((len=version_handshake(buf,len,wfd)) < 0) {
close(rfd);
close(wfd);
break;
}
if (protocol_ver >= 1) {
/* Tell run_erl size of terminal window */
signal(SIGWINCH, handle_sigwinch);
raise(SIGWINCH);
}
got_some = 1;
}
/*
* We successfully read at least one character. Write what we got.
*/
STATUS("Terminal write: \"");
if (write_all(1, buf, len) != len) {
fprintf(stderr, "Error in writing to terminal.\n");
close(rfd);
close(wfd);
break;
}
STATUS("\" OK\r\n");
}
}
}
/*
* Reset terminal characterstics
* XXX
*/
tcsetattr(0, TCSADRAIN, &tty_rmode);
return 0;
}