diff --git a/allover13.c b/allover13.c
index c65888f..851fdcb 100644
--- a/allover13.c
+++ b/allover13.c
@@ -52,7 +52,10 @@ int main(int argc, char * const argv[])
    Scale = 40.0;
    pitch = 45.0 * Scale;
    
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/arches.c b/arches.c
index fab86ee..39a06d1 100644
--- a/arches.c
+++ b/arches.c
@@ -38,7 +38,10 @@ int main(int argc, char * const argv[])
    }
 
    /* Select first pen and draw border */
-   plotbegin(1);
+   if (plotbegin(1) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/celticstep.c b/celticstep.c
index fc8f77b..25ec2c3 100644
--- a/celticstep.c
+++ b/celticstep.c
@@ -57,7 +57,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/circle_lines.c b/circle_lines.c
index 759a71b..ff00ff3 100644
--- a/circle_lines.c
+++ b/circle_lines.c
@@ -52,7 +52,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/coords.c b/coords.c
index 37c1d47..b8b48da 100644
--- a/coords.c
+++ b/coords.c
@@ -35,7 +35,10 @@ int main(int argc, char * const argv[])
       }
    }
    
-   plotbegin(1);
+   if (plotbegin(1) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/cs_rosette.c b/cs_rosette.c
index f3a7299..125a182 100644
--- a/cs_rosette.c
+++ b/cs_rosette.c
@@ -57,7 +57,10 @@ int main(int argc, char * const argv[])
    nrings = 4;
    nlines = 16;
    
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/curve_stitching.c b/curve_stitching.c
index d2708c7..9ac3998 100644
--- a/curve_stitching.c
+++ b/curve_stitching.c
@@ -49,7 +49,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/dala1.c b/dala1.c
index 5d622d4..5948937 100644
--- a/dala1.c
+++ b/dala1.c
@@ -42,7 +42,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/dala2.c b/dala2.c
index 50a89d2..80bfd3d 100644
--- a/dala2.c
+++ b/dala2.c
@@ -84,7 +84,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
 
diff --git a/dala2c.c b/dala2c.c
index 096375c..1853066 100644
--- a/dala2c.c
+++ b/dala2c.c
@@ -52,7 +52,10 @@ int main (int argc, char * const argv[])
       }
    }
 
-   plotbegin (0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize (&maxx, &maxy);
    
diff --git a/dala3.c b/dala3.c
index d67d9af..db8d881 100644
--- a/dala3.c
+++ b/dala3.c
@@ -42,7 +42,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/ellipse.c b/ellipse.c
index f52179a..384e4e7 100644
--- a/ellipse.c
+++ b/ellipse.c
@@ -38,7 +38,10 @@ int main(int argc, char * const argv[])
    }
 
    /* Select first pen and draw border */
-   plotbegin(1);
+   if (plotbegin(1) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/fraserspiral.c b/fraserspiral.c
index 50794db..e183ddb 100644
--- a/fraserspiral.c
+++ b/fraserspiral.c
@@ -39,7 +39,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/hyp.c b/hyp.c
index 7b79112..da0719e 100644
--- a/hyp.c
+++ b/hyp.c
@@ -42,7 +42,10 @@ int main(int argc, char *const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
    
    getplotsize(&X0, &Y0);
 
diff --git a/isogrid.c b/isogrid.c
index 4c16c02..d2d363c 100644
--- a/isogrid.c
+++ b/isogrid.c
@@ -40,7 +40,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(1);
+   if (plotbegin(1) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/libtest.c b/libtest.c
index 9a1afaf..ac4daaf 100644
--- a/libtest.c
+++ b/libtest.c
@@ -42,7 +42,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(1);
+   if (plotbegin(1) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/lissajous.c b/lissajous.c
index 767106f..3be0bd4 100644
--- a/lissajous.c
+++ b/lissajous.c
@@ -35,7 +35,10 @@ int main(int argc, char * const argv[])
    }
 
    /* Select first pen and draw border */
-   plotbegin(1);
+   if (plotbegin(1) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/lotus.c b/lotus.c
index c3e077d..2d0aef8 100644
--- a/lotus.c
+++ b/lotus.c
@@ -50,7 +50,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/morphpoly.c b/morphpoly.c
index 0c9b33e..05670e8 100644
--- a/morphpoly.c
+++ b/morphpoly.c
@@ -59,7 +59,10 @@ int main(int argc, char * const argv[])
 
    srand((unsigned int)time(NULL));
 
-   plotbegin(1);
+   if (plotbegin(1) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/op_moire.c b/op_moire.c
index 5537c61..2fbaf36 100644
--- a/op_moire.c
+++ b/op_moire.c
@@ -43,7 +43,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/pappus.c b/pappus.c
index 334d1ac..5b0d6b0 100644
--- a/pappus.c
+++ b/pappus.c
@@ -41,7 +41,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/pin_and_cotton.c b/pin_and_cotton.c
index 1698989..efcc5a7 100644
--- a/pin_and_cotton.c
+++ b/pin_and_cotton.c
@@ -62,7 +62,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/pin_circle.c b/pin_circle.c
index ac132e4..00230af 100644
--- a/pin_circle.c
+++ b/pin_circle.c
@@ -39,7 +39,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/piscis.c b/piscis.c
index cd6854b..fdd8576 100644
--- a/piscis.c
+++ b/piscis.c
@@ -34,7 +34,10 @@ int main(int argc, char * const argv[])
    }
 
    /* Select first pen and draw border */
-   plotbegin(1);
+   if (plotbegin(1) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/poly_oval.c b/poly_oval.c
index 961627b..5895814 100644
--- a/poly_oval.c
+++ b/poly_oval.c
@@ -46,7 +46,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(1);
+   if (plotbegin(1) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/qrplot.c b/qrplot.c
index d2479df..bea43e8 100644
--- a/qrplot.c
+++ b/qrplot.c
@@ -32,7 +32,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    plotPBM("qr_sample.pbm", 50.0, 0.0, 2.0);
    
diff --git a/spiralsq.c b/spiralsq.c
index 9436403..4c29e91 100644
--- a/spiralsq.c
+++ b/spiralsq.c
@@ -42,7 +42,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/sqinsq.c b/sqinsq.c
index 4d8d9ee..79ceb61 100644
--- a/sqinsq.c
+++ b/sqinsq.c
@@ -44,7 +44,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/star_grid.c b/star_grid.c
index f811b80..53764eb 100644
--- a/star_grid.c
+++ b/star_grid.c
@@ -52,7 +52,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/superellipse.c b/superellipse.c
index 969f908..aefa4a2 100644
--- a/superellipse.c
+++ b/superellipse.c
@@ -51,7 +51,10 @@ int main(int argc, char * const argv[])
    }
 
    /* Select first pen and draw border */
-   plotbegin(1);
+   if (plotbegin(1) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/sutpent.c b/sutpent.c
index 55c85e8..abea858 100644
--- a/sutpent.c
+++ b/sutpent.c
@@ -45,7 +45,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(1);
+   if (plotbegin(1) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/ternary_arcs.c b/ternary_arcs.c
index 09484b9..b31a97c 100644
--- a/ternary_arcs.c
+++ b/ternary_arcs.c
@@ -43,7 +43,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/twist.c b/twist.c
index 3da767c..4935ef0 100644
--- a/twist.c
+++ b/twist.c
@@ -37,7 +37,10 @@ int main(int argc, char * const argv[])
       }
    }
 
-   plotbegin(0);
+   if (plotbegin(0) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
 
    getplotsize(&maxx, &maxy);
    
diff --git a/zigzag.c b/zigzag.c
index df6c3fe..7c3d3ca 100644
--- a/zigzag.c
+++ b/zigzag.c
@@ -38,6 +38,11 @@ int main(int argc, char * const argv[])
       }
    }
 
+   if (plotbegin(1) < 0) {
+      fputs("Failed to initialise HPGL library\n", stderr);
+      exit(EXIT_FAILURE);
+   }
+
    if ((fp = fopen("zigzag.pgm", "r")) == NULL) {
       perror("zigzag.pgm");
       exit(EXIT_FAILURE);
@@ -47,8 +52,6 @@ int main(int argc, char * const argv[])
    fgets(lin, 128, fp);
    fgets(lin, 128, fp);
 
-   plotbegin(1);
-
    getplotsize(&maxx, &maxy);
    
    for (i = 0; i < 40; i++) {