Essed NPM | npm.io

essed

essed is a simple program with purpose similar to sed or awk

Performance - sed is strongly optimized C code. JavaScript is much slower. It's totally possible for essed to be 200 times slower than C-based tools.
Non-UTF8 encodings (at least yet)
Dealing with binary files

Portability - you can use essed in your npm scripts. Though, it won't be installed globally on your CI.

Loading code from file
assert - assert input match some criteria. If it doesn't, break pipeline, otherwise return untouched
find - find first line matching some criteria
limit parameter on filter - if number of matched items exceed limit, drop them down
limit parameter on map
takeWhile
takeUntil
findLast
reduce
Native support for line-delimited JSON
Provide Webpack compiled build to improve startup time
Provide way to load external modules

Remove whitespace from each line:

cat ~/.bashrc | essed --map "line.trim()"

Reverse lines:

cat ~/.bashrc | essed --map "$0.reverse()"

Remove comments (nulls and undefineds are filtered out from output):

cat ~/.zshrc | essed --map "value.trim().startsWith('#') ? null : line"

Color even lines (terminal):

cat ~/.zshrc | essed -m "i % 2 ? line.yellow : line"

Remove comments:

essed --filter "line.trim().startsWith('#')" ~/.zshrc

For your convenience we expose following "globals":

shared - empty object shared by many invocations
P, Bluebird - Bluebird instance
lodash, _ - lodash instance
hl, highland - highland instance
deburr, pad, trim, truncate, upperFirst, replace - exported from lodash
execFile, execFileSync - exported from native child_process
colors - colors instance
log - function that logs it's input on stderr and returns first argument.
fs - native Node.js module ** log(line) === line