a.bed

chr1	249132529	249132530	6425	0	+

a.medium.bed

chr1	249120154	249120155	21176	0	-
chr1	249132529	249132530	6425	0	+

b.bed

chr1	245010243	245010244	447	0	-
chr1	247242115	247242116	551	0	-
chr1	247271384	247271385	959	0	+
chr1	247495324	247495325	510	0	+

do_test.sh

echo "bedtools version:"
bedtools --version
echo "closestBed with one-line file input:"
closestBed -S -a a.bed -b b.bed |grep 249132529
echo "closestBed with two-line file input:"
closestBed -S -a a.medium.bed -b b.bed |grep 249132529
echo "closestBed, ignore strand"
closestBed -a a.medium.bed -b b.bed |grep 249132529

test_output.txt

bedtools version:
bedtools v2.24.0
closestBed with one-line file input:
chr1	249132529	249132530	6425	0	+	chr1	247242115	247242116	551	0	-
closestBed with two-line file input:
chr1	249132529	249132530	6425	0	+	.	-1	-1	.	-1	.
closestBed, ignore strand
chr1	249132529	249132530	6425	0	+	chr1	247495324	247495325	510	0	+