From 7f1449a1f3dc70202c19005d74c6afe7cb0f18c0 Mon Sep 17 00:00:00 2001 From: Pierre Habouzit Date: Sat, 11 Nov 2006 14:11:05 +0100 Subject: [PATCH] steal some bits from qemacs to open the pty. we gain non blocking IOs add rote_vt_read no more selects \o/ Signed-off-by: Pierre Habouzit --- demo/boxshell.c | 7 ++- madtty/madtty.c | 133 +++++++++++++++++++++++++++++++++++------------- madtty/madtty.h | 4 +- 3 files changed, 107 insertions(+), 37 deletions(-) diff --git a/demo/boxshell.c b/demo/boxshell.c index cdc980c..42c2579 100644 --- a/demo/boxshell.c +++ b/demo/boxshell.c @@ -78,7 +78,12 @@ int main(int argc, char *argv[]) /* create the terminal and have it run bash */ rt = rote_vt_create(h, w); - rote_vt_forkpty(rt, "/bin/bash --login"); + { + const char *path = "/bin/bash"; + const char *args[] = {"/bin/bash", "--login", NULL}; + + rote_vt_forkpty(rt, path, args); + } /* keep reading keypresses from the user and passing them to the terminal; * also, redraw the terminal to the window at each iteration */ diff --git a/madtty/madtty.c b/madtty/madtty.c index 2002e18..6556890 100644 --- a/madtty/madtty.c +++ b/madtty/madtty.c @@ -19,7 +19,9 @@ Copyright © 2006 Pierre Habouzit */ +#include #include +#include #ifdef USE_PTY #include #endif @@ -134,37 +136,100 @@ void rote_vt_draw(RoteTerm *rt, WINDOW *win, int srow, int scol, #endif -#ifdef USE_PTY +/******************************************************/ + +#define PTYCHAR1 "pqrstuvwxyz" +#define PTYCHAR2 "0123456789abcdef" + +/* allocate one pty/tty pair */ +static int get_pty(char *tty_str) +{ + int fd; + char ptydev[] = "/dev/pty??"; + char ttydev[] = "/dev/tty??"; + int len = strlen(ttydev); + const char *c1, *c2; + + for (c1 = PTYCHAR1; *c1; c1++) { + ptydev[len-2] = ttydev[len-2] = *c1; + for (c2 = PTYCHAR2; *c2; c2++) { + ptydev[len-1] = ttydev[len-1] = *c2; + if ((fd = open(ptydev, O_RDWR)) >= 0) { + if (access(ttydev, R_OK|W_OK) == 0) { + strcpy(tty_str, ttydev); + return fd; + } + close(fd); + } + } + } + return -1; +} -pid_t rote_vt_forkpty(RoteTerm *rt, const char *command) +static int +run_process(const char *path, const char **argv, int *fd_ptr, int *pid_ptr) { + int pty_fd, pid, i, nb_fds; + char tty_name[32]; struct winsize ws; - pid_t childpid; - ws.ws_row = rt->rows; - ws.ws_col = rt->cols; - ws.ws_xpixel = ws.ws_ypixel = 0; + pty_fd = get_pty(tty_name); + if (pty_fd < 0) + return -1; - childpid = forkpty(&rt->pd->pty, NULL, NULL, &ws); - if (childpid < 0) + fcntl(pty_fd, F_SETFL, O_NONBLOCK); + + /* set dummy screen size */ + ws.ws_col = 80; + ws.ws_row = 25; + ws.ws_xpixel = ws.ws_col; + ws.ws_ypixel = ws.ws_row; + ioctl(pty_fd, TIOCSWINSZ, &ws); + + pid = fork(); + if (pid < 0) return -1; - if (childpid == 0) { - /* we are the child, running under the slave side of the pty. */ + if (pid == 0) { + /* child process */ + nb_fds = getdtablesize(); + for (i = 0; i < nb_fds; i++) + close(i); + /* open pseudo tty for standard i/o */ + open(tty_name, O_RDWR); + dup(0); + dup(0); + + setsid(); - /* Cajole application into using linux-console-compatible escape - * sequences (which is what we are prepared to interpret) */ setenv("TERM", "linux", 1); + execv(path, (char *const*)argv); + fprintf(stderr, "\nexecv() failed.\nCommand: '%s'\n", argv[0]); + exit(1); + } + /* return file info */ + *fd_ptr = pty_fd; + *pid_ptr = pid; + return 0; +} + + +#ifdef USE_PTY - /* Now we will exec /bin/sh -c command. */ - execl("/bin/sh", "/bin/sh", "-c", command, NULL); +pid_t rote_vt_forkpty(RoteTerm *rt, const char *path, const char *argv[]) +{ + struct winsize ws; - fprintf(stderr, "\nexecl() failed.\nCommand: '%s'\n", command); - exit(127); /* error exec'ing */ + ws.ws_row = rt->rows; + ws.ws_col = rt->cols; + ws.ws_xpixel = ws.ws_ypixel = 0; + + if (run_process(path, argv, &rt->pd->pty, &rt->childpid)) { + return -1; } - /* if we got here we are the parent process */ - return (rt->childpid = childpid); + ioctl(rt->pd->pty, TIOCSWINSZ, &ws); + return rt->childpid; } void rote_vt_forsake_child(RoteTerm *rt) @@ -179,13 +244,9 @@ void rote_vt_forsake_child(RoteTerm *rt) void rote_vt_update(RoteTerm *rt) { - fd_set ifs; - struct timeval tvzero; char buf[512]; - int bytesread; + int nbread; int n = ROTE_VT_UPDATE_ITERATIONS; - if (rt->pd->pty < 0) - return; /* nothing to pump */ while (n--) { /* iterate at most ROVE_VT_UPDATE_ITERATIONS times. * As Phil Endecott pointed out, if we don't restrict this, @@ -195,21 +256,23 @@ void rote_vt_update(RoteTerm *rt) * calling rote_vt_update often, as the documentation * recommends :-) */ - /* check if pty has something to say */ - FD_ZERO(&ifs); FD_SET(rt->pd->pty, &ifs); - tvzero.tv_sec = 0; tvzero.tv_usec = 0; - - if (select(rt->pd->pty + 1, &ifs, NULL, NULL, &tvzero) <= 0) - return; /* nothing to read, or select() failed */ - - /* read what we can. This is guaranteed not to block, since - * select() told us there was something to read. */ - bytesread = read(rt->pd->pty, buf, 512); - if (bytesread <= 0) return; + nbread = rote_vt_read(rt, buf, sizeof(buf)); + if (nbread <= 0) + return; /* inject the data into the terminal */ - rote_vt_inject(rt, buf, bytesread); + rote_vt_inject(rt, buf, nbread); + } +} + +int rote_vt_read(RoteTerm *rt, char *buf, int buflen) +{ + if (rt->pd->pty < 0) { + errno = EINVAL; + return -1; } + + return read(rt->pd->pty, buf, buflen); } void rote_vt_write(RoteTerm *rt, const char *data, int len) diff --git a/madtty/madtty.h b/madtty/madtty.h index 373d1f3..cb34762 100644 --- a/madtty/madtty.h +++ b/madtty/madtty.h @@ -166,7 +166,7 @@ void rote_vt_destroy(RoteTerm *rt); * to execute the command and will exit with status 127. You can catch * that by installing a SIGCHLD handler if you want. */ -pid_t rote_vt_forkpty(RoteTerm *rt, const char *command); +pid_t rote_vt_forkpty(RoteTerm *rt, const char *path, const char *argv[]); /* Disconnects the RoteTerm from its forked child process. This function * should be called when the child process dies or something of the sort. @@ -183,6 +183,8 @@ void rote_vt_forsake_child(RoteTerm *rt); * read from the child process it will return immediately. */ void rote_vt_update(RoteTerm *rt); +int rote_vt_read(RoteTerm *rt, char *buf, int buflen); + /* Puts data into the terminal: if there is a forked process running, * the data will be sent to it. If there is no forked process, * the data will simply be injected into the terminal (as in -- 2.20.1