Bioinformatics insights
A safer guide to sed for genomics files
Use stream editing to repair chromosome prefixes, headers, genome-build strings, line endings, and other recurring file-format problems.
Why sed belongs in the toolkit
Bioinformatics files are often too large for manual editing. sed processes input line by line, making it useful for targeted transformations across VCF, BED, GTF, tabular outputs, and pipeline scripts.
Preview before in-place editing
Run the transformation without the in-place flag, inspect a representative subset, and keep the original file immutable. For production work, write to a new output path and capture the command in a script or workflow.
Common transformations
Typical uses include adding or removing chromosome prefixes, dropping comment lines for downstream tools, replacing a reference-build label, removing blank lines, and normalizing Windows line endings.
Validate the biological meaning
A syntactically correct edit can still be scientifically wrong. Confirm reference builds, contig naming conventions, delimiters, and expected record counts before and after every transformation.