Add tty line support

Not always is desirable to create a pseudo terminal, and some times
we want to open a terminal emulator over a tty line. With this new
patch is possible to do someting like:

	$ st -l /dev/ttyS0 115200

Without this option was needed to launch another terminal emulator
over st (for example minicom, picocom, cu, ...).

1 files changed, 54 insertions, 12 deletions

diff --git a/st.c b/st.c
index bb8c365..d22c605 100644
--- a/st.c
+++ b/st.c
@@ -352,6 +352,7 @@ static void draw(void);
 static void redraw(void);
 static void drawregion(int, int, int, int);
 static void execsh(void);
+static void stty(void);
 static void sigchld(int);
 static void run(void);
 
@@ -508,6 +509,7 @@ static char *opt_title = NULL;
 static char *opt_embed = NULL;
 static char *opt_class = NULL;
 static char *opt_font = NULL;
+static char *opt_line = NULL;
 static int oldbutton = 3; /* button event on startup: 3 = release */
 
 static char *usedfont = NULL;
@@ -1253,11 +1255,55 @@ sigchld(int a) {
         exit(EXIT_SUCCESS);
 }
 
+
+void
+stty(void)
+{
+        char cmd[_POSIX_ARG_MAX], **p, *q, *s;
+        size_t n, siz;
+
+        if((n = strlen(stty_args)) > sizeof(cmd)-1)
+                die("incorrect stty parameters\n");
+        memcpy(cmd, stty_args, n);
+        q = cmd + n;
+        siz = sizeof(cmd) - n;
+        for(p = opt_cmd; p && (s = *p); ++p) {
+                if((n = strlen(s)) > siz-1)
+                        die("stty parameter length too long\n");
+                *q++ = ' ';
+                q = memcpy(q, s, n);
+                q += n;
+                siz-= n + 1;
+        }
+        *q = '\0';
+        system(cmd);
+}
+
 void
 ttynew(void) {
         int m, s;
         struct winsize w = {term.row, term.col, 0, 0};
 
+        if(opt_io) {
+                term.mode |= MODE_PRINT;
+                iofd = (!strcmp(opt_io, "-")) ?
+                          STDOUT_FILENO :
+                          open(opt_io, O_WRONLY | O_CREAT, 0666);
+                if(iofd < 0) {
+                        fprintf(stderr, "Error opening %s:%s\n",
+                                opt_io, strerror(errno));
+                }
+        }
+
+        if (opt_line) {
+                if((cmdfd = open(opt_line, O_RDWR)) < 0)
+                        die("open line failed: %s\n", strerror(errno));
+                close(STDIN_FILENO);
+                dup(cmdfd);
+                stty();
+                return;
+        }
+
         /* seems to work fine on linux, openbsd and freebsd */
         if(openpty(&m, &s, NULL, NULL, &w) < 0)
                 die("openpty failed: %s\n", strerror(errno));
@@ -1267,6 +1313,7 @@ ttynew(void) {
                 die("fork failed\n");
                 break;
         case 0:
+                close(iofd);
                 setsid(); /* create a new process group */
                 dup2(s, STDIN_FILENO);
                 dup2(s, STDOUT_FILENO);
@@ -1281,16 +1328,6 @@ ttynew(void) {
                 close(s);
                 cmdfd = m;
                 signal(SIGCHLD, sigchld);
-                if(opt_io) {
-                        term.mode |= MODE_PRINT;
-                        iofd = (!strcmp(opt_io, "-")) ?
-                                  STDOUT_FILENO :
-                                  open(opt_io, O_WRONLY | O_CREAT, 0666);
-                        if(iofd < 0) {
-                                fprintf(stderr, "Error opening %s:%s\n",
-                                        opt_io, strerror(errno));
-                        }
-                }
                 break;
         }
 }
@@ -4009,9 +4046,11 @@ run(void) {
 
 void
 usage(void) {
-        die("%s " VERSION " (c) 2010-2015 st engineers\n" \
+        die("%s " VERSION " (c) 2010-2015 st engineers\n"
         "usage: st [-a] [-v] [-c class] [-f font] [-g geometry] [-o file]\n"
-        "          [-i] [-t title] [-w windowid] [-e command ...] [command ...]\n",
+        "          [-i] [-t title] [-w windowid] [-e command ...] [command ...]\n"
+        "       st [-a] [-v] [-c class] [-f font] [-g geometry] [-o file]\n"
+        "          [-i] [-t title] [-w windowid] [-l line] [stty_args ...]\n",
         argv0);
 }
 
@@ -4047,6 +4086,9 @@ main(int argc, char *argv[]) {
         case 'o':
                 opt_io = EARGF(usage());
                 break;
+        case 'l':
+                opt_line = EARGF(usage());
+                break;
         case 't':
                 opt_title = EARGF(usage());
                 break;