1 files changed, 104 insertions, 0 deletions
diff --git a/safetitle.c b/safetitle.c
new file mode 100644
index 0000000..b9d8be0
--- /dev/null
+++ b/safetitle.c
@@ -0,0 +1,104 @@
+/*
+ *  safetitle sets the title of the terminal window to the given string,
+ *  unless the terminal type is blacklisted.
+ */
+
+#include <err.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/select.h>
+#include <termios.h>
+#include <unistd.h>
+
+#define WSCONS_DA (char[]){27,91,62,50,52,59,50,48,59,48,99,0}
+#define SCREEN_DA (char[]){27,91,62,56,51,59,52,48,56,48,48,59,48,99,0}
+
+int screen = 0;
+
+int
+blacklisted(int fd)
+{
+	char *buf, c;
+	fd_set fds;
+	int i, r;
+	struct timeval timeout;
+
+	if((buf = malloc(200*sizeof(char)))==NULL)
+		err(1, "malloc");
+
+	/* check if GNU screen */
+	write(fd, "\033[>c", 4);
+	i = 0;
+	while(r = read(fd, &c, 1)){
+		if(r==-1)
+			return 1;
+		buf[i++] = c;
+		if(c=='c') break;
+	}
+	buf[i] = '\0';
+	screen = strcmp(buf, SCREEN_DA)==0;
+
+	/* ignore strange trailing nul before reading response */
+	FD_ZERO(&fds);
+	FD_SET(fd, &fds);
+	timeout.tv_sec = 0;
+	timeout.tv_usec = 0;
+	while(select(fd+1, &fds, NULL, NULL, &timeout)>0)
+		read(fd, &c, 1);
+
+	/* check (real) terminal type(s) */
+	if(screen) write(fd, "\033P\033[>c\033\\", 8);
+	else write(fd, "\033[>c", 4);
+
+	i = 0;
+	while(r = read(fd, &c, 1)){
+loop:
+		if(r==-1)
+			return 1;
+		buf[i++] = c;
+		if(c==99) break;
+	}
+	buf[i] = '\0';
+
+	if(strcmp(buf, WSCONS_DA)==0)
+		return 1;
+
+	/* go back and check remaining responses (if any) */
+check:
+	FD_ZERO(&fds);
+	FD_SET(fd, &fds);
+	timeout.tv_sec = 0;
+	timeout.tv_usec = 1; /* it takes a millisecond sometimes */
+	if(screen && select(fd+1, &fds, NULL, NULL, &timeout)>0){
+		/* ignore strange trailing nul before reading response */
+		if(read(fd, &c, 1)==-1)
+			return 1;
+		i = 0;
+		if(c==0) goto check;
+		else goto loop;
+	}
+
+	return 0;
+}
+
+void
+safetitle(char *title)
+{
+	int ttyfd;
+
+        if((ttyfd = open("/dev/tty", O_RDWR))==-1)
+                err(1, "open");
+
+	/* get device attributes for real terminal */
+	if(blacklisted(ttyfd))
+		return;
+
+	if(strncmp(title, "/home/", 6)==0)
+		title += 6;
+
+	/* set title */
+	if(screen) dprintf(ttyfd, "\033P\033]2;%s\007\033\\", title);
+	else dprintf(ttyfd, "\033]2;%s\007", title);
+}