informalsed

Informalsed is a term used in some online and educational contexts to describe the informal, ad hoc use of the Unix stream editor sed for quick text transformations outside formal programming or scripting workflows. It characterizes practices that emphasize speed and practicality over formal design or thorough documentation.

The term is not an official standard. It arises from casual discussions where participants apply sed with minimal planning, often in one-off edits or exploratory tasks. It carries no formal syntax beyond the base sed commands that are widely understood by practitioners. Informalsed is thus more about a mindset and workflow than a distinct tool or language.

Common situations include rapid edits to log files, configuration snippets, or pipeline outputs during debugging or data exploration. Typical operations involve substitution, deletion, and line-based insertion, performed in one-liners or short scripts. The emphasis is on getting a result quickly rather than producing a reusable, robust solution.

Because informalsed relies on informal practice, it can suffer from portability and maintenance issues. Differences between GNU sed and BSD sed, or between shell environments, can produce unexpected results. Users are advised to favor explicit scripts and comments when the tasks are nontrivial or intended for long-term use.

Examples: To substitute all occurrences of foo with bar in a file: sed -i 's/foo/bar/g' file. In a pipeline: cat file | sed 's/old/new/'. See also sed, stream editor, shell scripting.