function to read password from stdin, forget to add it

ipppd/readpw.c

@@ -0,0 +1,68 @@
+#include <termios.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+
+static int		tc_modified = 0;
+static struct termios	oldset;
+
+static void
+echo_disable(void)
+{
+	struct termios newset;
+
+	if (tcgetattr(STDIN_FILENO, &oldset) == 0 && (oldset.c_lflag & ECHO)) {
+		tc_modified = 1;
+		newset = oldset;
+		newset.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
+		(void) tcsetattr(STDIN_FILENO, TCSANOW, &newset);
+	}
+	return;
+}
+
+static void
+echo_restore(void)
+{
+	if (tc_modified != 0) {
+		tcsetattr(STDIN_FILENO, TCSANOW, &oldset);
+		tc_modified = 0;
+	}
+}
+
+static int
+readnoecho(char* buf, int maxl)
+{
+	char c = 0;
+	int n, i = 0;
+
+	echo_disable();
+	while (c != '\n') {
+		n = read(STDIN_FILENO, &c, 1);
+		if (n == -1 && (errno == EAGAIN || errno == EINTR))
+			continue;
+		if (n != 1)
+			break;
+		if (c == '\r')
+			break;
+		if (c == '\n')
+			break;
+		if (i < maxl)
+			buf[i++] = c;
+	}
+	buf[i] = '\0';
+	echo_restore();
+	fprintf(stderr, "\n");
+	fflush(stderr);
+	return i;
+}
+
+int
+readpassw(char *buf, int maxlen)
+{
+	fflush(stdout);
+	fflush(stderr);
+	fprintf(stderr, "password:");
+	fflush(stderr);
+	return(readnoecho(buf, maxlen));
+}
+