cmd line options, ...

1 files changed, 189 insertions, 61 deletions

diff --git a/xenscreen.c b/xenscreen.c
index dab818d..76e7893 100644
--- a/xenscreen.c
+++ b/xenscreen.c
@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdarg.h>
 #include <string.h>
 #include <unistd.h>
 #include <signal.h>
@@ -27,9 +28,38 @@ struct dom {
 static LIST_HEAD(doms);
 static int domcnt;
 
-static char *screenrc       = "/etc/xen/xenscreenrc";
+static char *screen_rc      = "/etc/xen/xenscreenrc";
+static char *screen_unlink  = NULL;
 static char *screen_session = "xencon";
-static char *screen_title   = "watch";
+static char *screen_title   = "mon";
+static char *screen_window  = NULL;
+static int  screen_detached;
+static int  screen_logging;
+
+static char builtin_screen_rc[] =
+"multiuser on\n"
+"\n"
+"# status line\n"
+"sorendition =s wb\n"
+"hardstatus lastline \"%{=b bw} xen |%{-} %-w%{= yb} %50>%n* %t %{-}%+w%<\"\n"
+"\n"
+"# logging\n"
+"logfile /var/log/xenscreen.%t\n"
+"logtstamp on\n"
+"\n"
+"# disable killing windows\n"
+"bind k\n"
+"bind K\n"
+"bind ^K\n"
+"\n"
+"# misc other useful settings\n"
+"shell /bin/bash\n"
+"defscrollback 5000\n"
+"compacthist on\n"
+"defutf8 on\n"
+"termcapinfo xterm hs@\n"
+"\n"
+;
 
 /* ------------------------------------------------------------- */
 
@@ -69,6 +99,32 @@ static void catchsig(int sig)
     termsig = sig;
 }
 
+/* ------------------------------------------------------------- */
+
+static int screen_command(char *arg0, ...)
+{
+    va_list args;
+    char *argv[64];
+    int i = 0;
+
+    argv[i++] = "screen";
+    argv[i++] = "-X";
+    argv[i++] = "-S";
+    argv[i++] = screen_session;
+
+    argv[i++] = arg0;
+    va_start(args, arg0);
+    while (i < array_size(argv)) {
+	argv[i] = va_arg(args, char*);
+	if (NULL == argv[i])
+	    break;
+	i++;
+    }
+    va_end(args);
+
+    return run_application_va(1, "screen", argv);
+}
+
 static void try_attach_screen(struct dom *dom, int boot)
 {
     int rc;
@@ -95,10 +151,13 @@ static void try_attach_screen(struct dom *dom, int boot)
 	return;
     }
 
-    rc = run_application(1, "screen", "screen",
-			 "-X", "-S", screen_session,
-			 "screen", "-L", "-t", dom->name, dom->tty,
-			 NULL);
+    if (screen_logging)
+	rc = screen_command("screen", "-L", "-t", dom->name, dom->tty,
+			    NULL);
+    else
+	rc = screen_command("screen", "-t", dom->name, dom->tty,
+			    NULL);
+
 #if 0
     /*
      * Hmm, not exactly the most elegant way to do this, has
@@ -109,10 +168,7 @@ static void try_attach_screen(struct dom *dom, int boot)
      * seems screen can't do that though :-(
      */
     if (!boot)
-	rc = run_application(1, "screen", "screen",
-			     "-X", "-S", screen_session,
-			     "other",
-			     NULL);
+	rc = screen_command("other", NULL);
 #endif
 
     dom->connected = 1;
@@ -133,34 +189,45 @@ static void try_release_domain(struct dom *dom)
 
 static void builtin_screen_setup(void)
 {
-    static char *config[] = {
-	"sorendition =s wb",
-	"hardstatus lastline \"%{=b bw} xen |%{-} %-w%{= yb} %50>%n* %t %{-}%+w%<\"",
-	"logfile /var/log/xenscreen.%t",
-	NULL /* EOF */,
-    };
-    char cmdline[256];
-    int line,try,rc;
-
-#if 1
-    /* FIXME: Hmm, doesn't work reliable without that one ... */
-    sleep(1);
-#endif
+    char *rc = strdup("/tmp/xenscreen-XXXXXX");
+    int fd;
 
-    for (line = 0; config[line] != NULL; line++) {
-	for (try = 0; try < 5; try++) {
-	    snprintf(cmdline, sizeof(cmdline), "screen -X -S %s %s",
-		     screen_session, config[line]);
-	    rc = run_cmdline(1,cmdline);
-	    if (0 == rc)
-		break;
-	    sleep(1);
-	}
+    fd = mkstemp(rc);
+    if (-1 == fd) {
+	fprintf(stderr,"mkstmp(%s): %s\n", rc, strerror(errno));
+	return;
     }
+    write(fd, builtin_screen_rc, sizeof(builtin_screen_rc));
+    close(fd);
+
+    fprintf(stderr, "Config file \"%s\" doesn't exist, using builtin config (%s).\n",
+	    screen_rc, rc);
+    screen_rc     = rc;
+    screen_unlink = rc;
+    return;
 }
 
 /* ------------------------------------------------------------- */
 
+static void usage(FILE *fp)
+{
+    fprintf(fp,
+	    "I'm managing xen consoles using screen.\n"
+	    "\n"
+	    "usage: xenscreen [options]\n"
+	    "options:\n"
+	    "   -h            print this text\n"
+	    "   -b            print builtin screen config file\n"
+	    "   -L            enable console output logging\n"
+	    "   -c screenrc   screen config file              [%s]\n"
+	    "   -S session    screen session name             [%s]\n"
+	    "   -p window     preselect screen window\n"
+	    "\n"
+	    "-- \n"
+	    "(c) 2006 Gerd Hoffmann <kraxel@suse.de>\n",
+	    screen_rc, screen_session);
+}
+
 int main(int argc, char *argv[])
 {
     struct sigaction act,old;
@@ -168,40 +235,99 @@ int main(int argc, char *argv[])
     struct xs_handle *xenstore = NULL;
     xs_transaction_t xst;
     char **vec = NULL;
-    int domid;
+    int domid, nac, c;
     char path[BUFSIZE], value[BUFSIZE];
     unsigned int count, i, rc;
     struct dom *dom;
     time_t last_ctrl_c = 0;
+    char **nav;
+
+    for (;;) {
+        if (-1 == (c = getopt(argc, argv, "hdbLc:S:u:p:")))
+            break;
+        switch (c) {
+        case 'c':
+	    screen_rc = optarg;
+            break;
+        case 'S':
+	    screen_session = optarg;
+            break;
+	case 'u':
+	    screen_unlink = optarg;
+	    break;
+	case 'p':
+	    screen_window = optarg;
+	    break;
+	case 'L':
+	    screen_logging = 1;
+	    break;
+	case 'd':
+	    screen_detached = 1;
+	    break;
+	case 'b':
+	    printf("%s", builtin_screen_rc);
+	    exit(0);
+        case 'h':
+            usage(stdout);
+            exit(0);
+        default:
+            usage(stderr);
+            exit(1);
+        }
+    }
 
     if (!have_application("screen")) {
-	fprintf(stderr, "screen not installed, exiting\n");
+	fprintf(stderr, "screen not found in $PATH (not installed?), exiting.\n");
 	exit(1);
     }
 
     if (NULL == getenv("STY") || NULL == strstr(getenv("STY"),screen_session)) {
-	/* not running inside screen, try to attach */
-	rc = run_application(1, "screen", "screen",
-			     "-S", screen_session,
-			     "-r", "-p", "=",
-			     NULL);
-	if (0 == rc)
-	    exit(0);
+	/* not running inside screen */
+	if (!screen_detached) {
+	    /* try to attach */
+	    rc = run_application(1, "screen", "screen",
+				 "-S", screen_session,
+				 "-r", "-p", "=",
+				 NULL);
+	    if (0 == rc)
+		exit(0);
+	} else {
+	    /* This is a nop: just check if screen is running */
+	    rc = screen_command("select", ".", NULL);
+	    if (0 == rc) {
+		fprintf(stderr,"Screen session \"%s\" already active, exiting.\n",
+			screen_session);
+		exit(0);
+	    }
+	}
 
 	/* failing that, start a new screen session */
-	if (0 != access(screenrc, R_OK))
-	    screenrc = "/dev/null";
-	execlp("screen", "screen",
-	       "-S", screen_session,
-	       "-c", screenrc,
-	       "-t", screen_title, argv[0],
-	       NULL);
-	perror("execlp(screen)");
+	fprintf(stderr,"Starting new screen session \"%s\".\n", screen_session);
+	if (0 != access(screen_rc, R_OK))
+	    builtin_screen_setup();
+	nav = malloc(sizeof(char*) * (argc + 16));
+	nac = 0;
+	nav[nac++] = "screen";
+	if (screen_detached) {
+	    nav[nac++] = "-d";
+	    nav[nac++] = "-m";
+	}
+	nav[nac++] = "-S";
+	nav[nac++] = screen_session;
+	nav[nac++] = "-c";
+	nav[nac++] = screen_rc;
+	nav[nac++] = "-t";
+	nav[nac++] = screen_title;
+	for (i = 0; argv[i] != NULL;)
+	    nav[nac++] = argv[i++];
+	if (screen_unlink) {
+	    nav[nac++] = "-u";
+	    nav[nac++] = screen_unlink;
+	}
+	nav[nac++] = NULL;
+	execvp(nav[0], nav);
+	perror("execvp(screen)");
 	exit(1);
-
-    } else if (0 != access(screenrc, R_OK)) {
-	/* no screenrc: do mini setup */
-	builtin_screen_setup();
     }
 
     /* setup signal handler */
@@ -244,14 +370,13 @@ int main(int argc, char *argv[])
 	xenstore_read(xenstore, path, dom->tty, sizeof(dom->tty));
 	try_attach_screen(dom, 1);
     }
-    rc = run_application(1, "screen", "screen",
-			 "-X", "-S", screen_session,
-			 "select", "0",
-			 NULL);
-    rc = run_application(1, "screen", "screen",
-			 "-X", "-S", screen_session,
-			 "windowlist", "-b",
-			 NULL);
+
+    if (screen_window)
+	rc = screen_command("select", screen_window, NULL);
+    if (!screen_window || 0 != rc) {
+	rc = screen_command("select", "0", NULL);
+	rc = screen_command("windowlist", "-b", NULL);
+    }
 
     /* main loop */
     fprintf(stderr,"ok, watching out for changes now\n");
@@ -332,5 +457,8 @@ int main(int argc, char *argv[])
 	try_attach_screen(dom, 0);
 	try_release_domain(dom);
     }
+
+    if (screen_unlink)
+	unlink(screen_unlink);
     return 0;
 }