Error message if NCP environment variable isn't set.

apps/discard.c

@@ -63,6 +63,8 @@ int main (int argc, char **argv)
     fprintf (stderr, "NCP initialization error: %s.\n", strerror (errno));
     if (errno == ECONNREFUSED)
       fprintf (stderr, "Is the NCP server started?\n");
+    else if (errno == EFAULT)
+      fprintf (stderr, "Is the NCP environment variable set?\n");
     exit (1);
   }
 

apps/echo.c

@@ -136,6 +136,8 @@ int main (int argc, char **argv)
     fprintf (stderr, "NCP initialization error: %s.\n", strerror (errno));
     if (errno == ECONNREFUSED)
       fprintf (stderr, "Is the NCP server started?\n");
+    else if (errno == EFAULT)
+      fprintf (stderr, "Is the NCP environment variable set?\n");
     exit (1);
   }
 

apps/finger.c

@@ -22,6 +22,8 @@ int main (int argc, char **argv)
     fprintf (stderr, "NCP initialization error: %s.\n", strerror (errno));
     if (errno == ECONNREFUSED)
       fprintf (stderr, "Is the NCP server started?\n");
+    else if (errno == EFAULT)
+      fprintf (stderr, "Is the NCP environment variable set?\n");
     exit (1);
   }
 

apps/finser.c

@@ -20,6 +20,8 @@ int main (int argc, char **argv)
     fprintf (stderr, "NCP initialization error: %s.\n", strerror (errno));
     if (errno == ECONNREFUSED)
       fprintf (stderr, "Is the NCP server started?\n");
+    else if (errno == EFAULT)
+      fprintf (stderr, "Is the NCP environment variable set?\n");
     exit (1);
   }
 

apps/gateway.c

@@ -231,6 +231,8 @@ int main (int argc, char **argv)
     fprintf (stderr, "NCP initialization error: %s.\n", strerror (errno));
     if (errno == ECONNREFUSED)
       fprintf (stderr, "Is the NCP server started?\n");
+    else if (errno == EFAULT)
+      fprintf (stderr, "Is the NCP environment variable set?\n");
     exit (1);
   }
 

apps/ping.c

@@ -71,6 +71,8 @@ int main (int argc, char **argv)
     fprintf (stderr, "NCP initialization error: %s.\n", strerror (errno));
     if (errno == ECONNREFUSED)
       fprintf (stderr, "Is the NCP server started?\n");
+    else if (errno == EFAULT)
+      fprintf (stderr, "Is the NCP environment variable set?\n");
     exit (1);
   }
 

apps/telnet.c

@@ -550,6 +550,8 @@ int main (int argc, char **argv)
     fprintf (stderr, "NCP initialization error: %s.\n", strerror (errno));
     if (errno == ECONNREFUSED)
       fprintf (stderr, "Is the NCP server started?\n");
+    else if (errno == EFAULT)
+      fprintf (stderr, "Is the NCP environment variable set?\n");
     exit (1);
   }
 

src/libncp.c

@@ -2,6 +2,7 @@
 
 #include <fcntl.h>
 #include <stdio.h>
+#include <errno.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <unistd.h>
@@ -52,6 +53,9 @@ int ncp_init (const char *path)
   server.sun_family = AF_UNIX;
   if (path == NULL)
     path = getenv ("NCP");
+  errno = EFAULT;
+  if (path == NULL)
+    return -1;
   strncpy (server.sun_path, path, sizeof server.sun_path - 1);
   if (connect (fd, (struct sockaddr *) &server, sizeof server) == -1)
     return -1;