Change .bam File Header

Each .bam file has an important header that describes a number of characteristics about the read sequences it contains.  The header is usually multiple lines and has information no chromosomes and samples included in the .bam file.   Samtools can be used to view the header of a .bam file with the following command.

If the need arises, Samtools can also be used to modify the header of a .bam file.  Samtools uses the reheader command to do this.  Below is an example where I changed the length of chrM in the header from 16569 to 16571 base pairs.