# bedtools > A swiss-army knife of tools for genomic-analysis tasks. > Used to intersect, group, convert and count data in BAM, BED, GFF/GTF, VCF format. > More information: . - Intersect file [a] and file(s) [b] regarding the sequences' [s]trand and save the result to a specific file: `bedtools intersect -a {{path/to/file_A}} -b {{path/to/file_B1 path/to/file_B2 ...}} -s > {{path/to/output_file}}` - Intersect two files with a [l]eft [o]uter [j]oin, i.e. report each feature from `file1` and NULL if no overlap with `file2`: `bedtools intersect -a {{path/to/file1}} -b {{path/to/file2}} -loj > {{path/to/output_file}}` - Using more efficient algorithm to intersect two pre-sorted files: `bedtools intersect -a {{path/to/file1}} -b {{path/to/file2}} -sorted > {{path/to/output_file}}` - [g]roup a file based on the first three and the fifth [c]olumn and apply the sum [o]peration on the sixth column: `bedtools groupby -i {{path/to/file}} -c 1-3,5 -g 6 -o sum` - Convert bam-formatted [i]nput file to a bed-formatted one: `bedtools bamtobed -i {{path/to/file.bam}} > {{path/to/file.bed}}` - Find for all features in `file1.bed` the closest one in `file2.bed` and write their [d]istance in an extra column (input files must be sorted): `bedtools closest -a {{path/to/file1.bed}} -b {{path/to/file2.bed}} -d`