Show HN: Jwalk, a Streaming JSON Parser for Unix

jwalk.sh

2 pointssstephenson2 comments

A JSON parser in Bash, impressive. I've just finished an HTTP server in Bash and had to rely on jq for parsing JSON requests, but maybe would love a pure POSIX solution instead. Do you happen to have any benchmarks?

Performance depends on what toolset you’re using and how large your data set is.

For small JSON documents, like a package.json file, jwalk is around ten times slower on my machine: 0.03 seconds, vs 0.004 seconds for jq.

For larger documents, like the 1.5 MB GitHub API response tree.json [1] in the jwalk corpus, jwalk on mawk takes 0.37 seconds vs jq’s 0.11 seconds, but jwalk uses just 1.18 MB of memory, vs jq’s 5.81 MB.

Other interpreted parsers don’t fare as well: JSON.awk [2], which only runs on gawk, takes 0.8 seconds and 27 MB to parse tree.json; JSON.sh [3] takes 201 (!) seconds and 43 (!) MB, and JSONPath.sh [4] takes 7.4 seconds and uses 1.7 MB.

[1] https://raw.githubusercontent.com/shellbound/jwalk/master/te...

[2] https://github.com/step-/JSON.awk

[3] https://github.com/dominictarr/JSON.sh

[4] https://github.com/mclarkson/JSONPath.sh

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