diff --git a/test/bamtobed/test-bamtobed.sh b/test/bamtobed/test-bamtobed.sh
index 0d028e74e038fb0026bd1f521812adde6f4deff3..358d8a7ed5883a41ebfc806b0f5dd775da4aad24 100644
--- a/test/bamtobed/test-bamtobed.sh
+++ b/test/bamtobed/test-bamtobed.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/bed12tobed6/test-bed12tobed6.sh b/test/bed12tobed6/test-bed12tobed6.sh
index 1cc53e86472c5f8905a0ab9d533ec0ffb0727a9c..ae7757b7323b2be9f21ea511a4f255ef4ed7eb7b 100644
--- a/test/bed12tobed6/test-bed12tobed6.sh
+++ b/test/bed12tobed6/test-bed12tobed6.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/closest/test-closest.sh b/test/closest/test-closest.sh
index e2d50d772b3895f1ee047be3ae88585a038b0057..0c094d0488edbdc5c16ccab02c23ab1e382c7ee4 100644
--- a/test/closest/test-closest.sh
+++ b/test/closest/test-closest.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/cluster/test-cluster.sh b/test/cluster/test-cluster.sh
index b8e5a6244196b5329fbac2fc2d82f729dc24f8df..07c425b48bd8cc797dc5c5dd3fdb6651cd1ca7f7 100644
--- a/test/cluster/test-cluster.sh
+++ b/test/cluster/test-cluster.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/coverage/test-coverage.sh b/test/coverage/test-coverage.sh
index 969e1c1c14cf8ad898b9556fdc7c70c9275086c3..4c43bd4b96be2ae048871b4b56ade7c788f824a3 100644
--- a/test/coverage/test-coverage.sh
+++ b/test/coverage/test-coverage.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/expand/test-expand.sh b/test/expand/test-expand.sh
index a8c118392ff92c6745b9955984609503c2703f7d..26ac22e3ee6349b19d3374da2df5e5d3f761b240 100644
--- a/test/expand/test-expand.sh
+++ b/test/expand/test-expand.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/flank/test-flank.sh b/test/flank/test-flank.sh
index c9c68551b8dd6f90dc75eaea07876e7bf45ac5c4..2101fd77d558387010d37b19ea00fa5e7d4ff317 100644
--- a/test/flank/test-flank.sh
+++ b/test/flank/test-flank.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/general/test-general.sh b/test/general/test-general.sh
index e1e9ef2ba2a60fe7c8a281039e8df4f5af973354..a9233dc2e15ca8b48d646beed560b6cb83897c7b 100644
--- a/test/general/test-general.sh
+++ b/test/general/test-general.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/genomecov/test-genomecov.sh b/test/genomecov/test-genomecov.sh
index b7102d5d0f95918721a94e62f9336de665671ede..2c00c24d9872f092abda6b486504280e0af1a5bf 100644
--- a/test/genomecov/test-genomecov.sh
+++ b/test/genomecov/test-genomecov.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/getfasta/test-getfasta.sh b/test/getfasta/test-getfasta.sh
index 64dbcd55995dbeee46b07be902bfbdbbb040f012..a661b22dfc9659cac92e69e215a90529c70e303c 100644
--- a/test/getfasta/test-getfasta.sh
+++ b/test/getfasta/test-getfasta.sh
@@ -6,6 +6,8 @@
 # aggggggggg
 # cggggggggg
 
+BT=${BT-../../bin/bedtools}
+
 check()
 {
 	if $1 = $2; then
@@ -16,7 +18,7 @@ check()
 }
 
 echo "    getfasta.t01...\c"
-LINES=$(echo $'chr1\t1\t10' | ../../bin/bedtools getfasta -fi t.fa -bed stdin -fo - | awk 'END{ print NR }')
+LINES=$(echo $'chr1\t1\t10' | $BT getfasta -fi t.fa -bed stdin -fo - | awk 'END{ print NR }')
 if [ "$LINES" != "2" ]; then
     echo fail
 else
@@ -24,7 +26,7 @@ else
 fi
 
 echo "    getfasta.t02...\c"
-LEN=$(../../bin/bedtools getfasta -split -fi t.fa -bed blocks.bed -fo stdout | awk '(NR == 2){ print length($0) }')
+LEN=$($BT getfasta -split -fi t.fa -bed blocks.bed -fo stdout | awk '(NR == 2){ print length($0) }')
 if [ "$LINES" != "2" ]; then
     echo fail
 else
@@ -32,7 +34,7 @@ else
 fi
 
 echo "    getfasta.t03...\c"
-SEQ=$(../../bin/bedtools getfasta -split -fi t.fa -bed blocks.bed -fo stdout | awk '(NR == 4){ print $0 }')
+SEQ=$($BT getfasta -split -fi t.fa -bed blocks.bed -fo stdout | awk '(NR == 4){ print $0 }')
 if [ "$SEQ" != "cta" ]; then
     echo fail
 else
@@ -41,7 +43,7 @@ fi
 
 # test -fo -
 echo "    getfasta.t04...\c"
-SEQ=$(../../bin/bedtools getfasta -split -fi t.fa -bed blocks.bed -fo - | awk '(NR == 4){ print $0 }')
+SEQ=$($BT getfasta -split -fi t.fa -bed blocks.bed -fo - | awk '(NR == 4){ print $0 }')
 if [ "$SEQ" != "cta" ]; then
     echo fail
 else
@@ -51,9 +53,9 @@ fi
 
 # test -split with -s -
 echo "    getfasta.t05...\c"
-SEQ=$(../../bin/bedtools getfasta -split -s -fi t.fa -bed blocks.bed -fo - | awk '(NR == 4){ print $0 }')
+SEQ=$($BT getfasta -split -s -fi t.fa -bed blocks.bed -fo - | awk '(NR == 4){ print $0 }')
 if [ "$SEQ" != "tag" ]; then
     echo fail
 else
     echo ok
-fi
\ No newline at end of file
+fi
diff --git a/test/groupBy/test-groupby.sh b/test/groupBy/test-groupby.sh
index f95782a9a3853a0cf2fd0e68a530a58f70da5fdc..a20f7cca7329f8dda6680894aa2ee82ebf4ea49e 100644
--- a/test/groupBy/test-groupby.sh
+++ b/test/groupBy/test-groupby.sh
@@ -1,7 +1,9 @@
-lines_a=$(../../bin/groupBy -g 3-1 -o collapse -c 4 -i ../map/values3.bed | wc -l)
-lines_b=$(../../bin/groupBy -g 1-3 -o collapse -c 4 -i ../map/values3.bed | wc -l)
-lines_c=$(../../bin/groupBy -g 1,2,3 -o collapse -c 4 -i ../map/values3.bed | wc -l)
-lines_d=$(../../bin/groupBy -g 1-2,3 -o collapse -c 4 -i ../map/values3.bed | wc -l)
+BT=${BT-../../bin/bedtools}
+
+lines_a=$($BT groupby -g 3-1 -o collapse -c 4 -i ../map/values3.bed | wc -l)
+lines_b=$($BT groupby -g 1-3 -o collapse -c 4 -i ../map/values3.bed | wc -l)
+lines_c=$($BT groupby -g 1,2,3 -o collapse -c 4 -i ../map/values3.bed | wc -l)
+lines_d=$($BT groupby -g 1-2,3 -o collapse -c 4 -i ../map/values3.bed | wc -l)
 
 check(){
     if [ "$1" != "$2" ]; then
@@ -15,13 +17,13 @@ check $lines_a $lines_d
 
 
 H=$(head -n 1 values3.header.bed)
-A=$(../../bin/bedtools groupby -i values3.header.bed -g 1,2,3 -c 4 -o concat -inheader | head -n 1)
+A=$($BT groupby -i values3.header.bed -g 1,2,3 -c 4 -o concat -inheader | head -n 1)
 
 if [ "$A" != $'chr1\t0\t10\ta1' ]; then
         echo "fail groupby"
 fi
 
-B=$(../../bin/bedtools groupby -i values3.header.bed -g 1,2,3 -c 4 -o concat -header | head -n 1)
+B=$($BT groupby -i values3.header.bed -g 1,2,3 -c 4 -o concat -header | head -n 1)
 
 if [ "$B" != $'#chrom\tstart\tend\tconcat(A)' ]; then
         echo "fail groupby"
diff --git a/test/intersect/test-intersect.sh b/test/intersect/test-intersect.sh
index cfd10793311e4297b1e7a4bc99e0b400052267d2..2d15187a77cfbde250d70ac344ef69f3b53cec75 100644
--- a/test/intersect/test-intersect.sh
+++ b/test/intersect/test-intersect.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/jaccard/test-jaccard.sh b/test/jaccard/test-jaccard.sh
index e44dc0499a83838e63c559de6901af8f6cf5b03c..ed3ba134da4928d79b4ccff5cb742786c25e143f 100644
--- a/test/jaccard/test-jaccard.sh
+++ b/test/jaccard/test-jaccard.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/map/test-map.sh b/test/map/test-map.sh
index 7fc286b5d2a7123bde7b3d49c99fe0dcbb5c40e3..e4e2564ad505b5ad027513c44700a7a9ed1dbd8f 100644
--- a/test/map/test-map.sh
+++ b/test/map/test-map.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/merge/test-merge.sh b/test/merge/test-merge.sh
index 91cf87dfbf71f928771c0e8862d53ab9e5987edb..b616be0aead4ec879dd712e5b28cdc42d5b68428 100644
--- a/test/merge/test-merge.sh
+++ b/test/merge/test-merge.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/multicov/test-multicov.sh b/test/multicov/test-multicov.sh
index d2db630609c57307de6d5be93e264a797c1ba9d6..c32ca9245e497e0213421d1df25919672ad28fdd 100644
--- a/test/multicov/test-multicov.sh
+++ b/test/multicov/test-multicov.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/slop/test-slop.sh b/test/slop/test-slop.sh
index 51997f32a1329614d343e4579ab5c48af14e6c59..d11ce3af64f7b3a044f736f5cc9bf50ca01cde0b 100644
--- a/test/slop/test-slop.sh
+++ b/test/slop/test-slop.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {
diff --git a/test/subtract/test-subtract.sh b/test/subtract/test-subtract.sh
index 80281c03c381f01489a5698c87974148108f4d42..32f132443ff19627f257130763fa99772cf1ade9 100644
--- a/test/subtract/test-subtract.sh
+++ b/test/subtract/test-subtract.sh
@@ -1,4 +1,4 @@
-BT=../../bin/bedtools
+BT=${BT-../../bin/bedtools}
 
 check()
 {