Changed usage to exit with 1 when command line used incorrectly

lesions_0.1

@@ -14,7 +14,7 @@
 if [ _${2} = _ ] ; then
     echo "Usage:  lesions <t1_root> <t2_root> [-f]"
     echo "-f   :  second image is FLAIR not t2"
-    exit
+    exit 1
 fi
 
 nclasses=3

lesions_0.2

@@ -15,7 +15,7 @@ if [ _$2 = _ ] ; then
     echo "Usage:  lesions <t1_root> <t2_root> [-f] [-lt <thr>]"
     echo "-f        :  second image is FLAIR not T2"
     echo "-lt <thr> :  set lesion threshold (default 0.5)"
-    exit
+    exit 1
 fi
 
 A=$1

lesions_0.3

@@ -16,7 +16,7 @@ if [ _$2 = _ ] ; then
     echo "Usage:  lesions <t1_root> <t2_root> [-f] [-lt <thr>]"
     echo "-f        :  second image is FLAIR not T2"
     echo "-lt <thr> :  set lesion threshold (default 0.5)"
-    exit
+    exit 1
 fi
 
 A=$1

siena

@@ -21,7 +21,7 @@ Usage() {
     echo "-b <b>                : ignore from b (mm) downwards in MNI152/Talairach space; b should probably be -ve"
     echo "-S \"sienadiffopts\"    : options to pass to siena_diff timepoint differencing (inside double-quotes), e.g. -S \"-s -i 20\""
     echo ""
-    exit
+    exit 1
 }
 
 if [ _$FSLDIR = _ ] ; then

siena_flow2std

@@ -12,7 +12,7 @@
 Usage() {
     echo "Usage: siena_flow2std <fileroot2> <fileroot2> [-d]"
     echo "-d : debug (don't delete intermediate files)"
-    exit
+    exit 1
 }
 
 if [ _$FSLDIR = _ ] ; then

sienax

@@ -22,7 +22,7 @@ Usage() {
     echo "-lm <mask>      : use lesion (or lesion+CSF) mask to remove incorrectly labelled \"grey matter\" voxels"
     echo "-S \"segopts\"    : options to pass to FAST segmentation (inside double-quotes), e.g. -S \"-i 20\""
     echo ""
-    exit
+    exit 1
 }
 
 if [ _$FSLDIR = _ ] ; then