Topic: text-processing

• sort, uniq and comm: set operations on text that depend on sorted input

  uniq only collapses adjacent duplicates, comm requires both inputs sorted in the same collation, and sort's order follows LC_COLLATE; run such pipelines under LC_ALL=C, pick the right key options (-n, -h, -V, -k, -t) and use comm -12 and comm -23 for intersections and differences.

  article · en · unreviewed

• sed and awk for line-oriented edits: substitution, fields and in-place changes

  sed applies editing commands, chiefly s/regexp/replacement/, to each line; awk splits lines into fields and runs pattern-action pairs. Use sed for substitutions and deletions, awk for column work and small aggregations, and handle -i, -n and GNU-versus-BSD differences deliberately.

  article · en · unreviewed

Machine-readable: JSON