OSH Parser Performance

We time $sh -n $file for various files under various shells, and repeat then run under cachegrind for stable metrics.

Source code: oils/benchmarks/osh-parser.sh

Raw files

Summary

Instructions Per Line (via cachegrind)

Lower numbers are generally better, but each shell recognizes a different language, and OSH uses a more thorough parsing algorithm. In thousands of "I refs".

shell label total lines thousand irefs per line
bash 118,863 7.3
dash 111,674 2.4
osh-native 16,905 12.9
osh-nosouffle 16,905 15.0

(zsh isn't measured because zsh -n unexpectedly forks.)

Average Parsing Rate, Measured on Two Machines (lines/ms)

Shell startup time is included in the elapsed time measurements, but long files are chosen to minimize its effect.

shell label total lines host no-host
dash 111,674 2,590
bash 118,863 1,274
osh-native 16,905 342
osh-nosouffle 16,905 327
osh-cpython 4,802 20

Per-File Measurements

Time and Memory

shell label elapsed ms user ms sys ms max rss MB num lines filename
dash 2 2 0 2 2,698 Build.sh
bash 3 3 0 3 2,698 Build.sh
osh-native 7 6 1 9 2,698 Build.sh
osh-nosouffle 8 4 4 9 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 4 0 3 2,512 abuild
osh-native 9 7 2 9 2,512 abuild
osh-nosouffle 10 9 1 9 2,512 abuild
dash 9 9 0 2 20,489 configure
bash 17 16 1 4 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
dash 1 1 1 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 4 2 8 1,733 functions
osh-nosouffle 7 3 4 9 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 9 8 1 4 9,661 ltmain.sh
dash 1 0 1 1 1,679 t4014-format-patch.sh
bash 2 0 2 3 1,679 t4014-format-patch.sh
osh-native 4 2 2 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 113 95 18 19 1,679 t4014-format-patch.sh
dash 1 0 1 2 3,123 t9300-fast-import.sh
bash 2 1 1 3 3,123 t9300-fast-import.sh
osh-native 4 3 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 1 3 8 3,123 t9300-fast-import.sh
osh-cpython 124 107 17 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-nosouffle 19 13 6 13 5,160 test-cmd-util.sh
osh-native 19 13 6 12 5,160 test-cmd-util.sh

Instruction Counts

shell label irefs num lines filename
dash 6,684,258 2,698 Build.sh
bash 19,403,577 2,698 Build.sh
osh-native 31,536,416 2,698 Build.sh
osh-nosouffle 35,783,745 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,677,490 2,512 abuild
osh-nosouffle 52,232,277 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,436,957 1,733 functions
osh-nosouffle 28,821,599 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,044,766 1,679 t4014-format-patch.sh
osh-nosouffle 11,020,267 1,679 t4014-format-patch.sh
bash 11,082,677 1,679 t4014-format-patch.sh
dash 4,585,030 3,123 t9300-fast-import.sh
osh-native 11,849,476 3,123 t9300-fast-import.sh
osh-nosouffle 13,000,558 3,123 t9300-fast-import.sh
bash 16,659,503 3,123 t9300-fast-import.sh
bash 73,195,614 5,160 test-cmd-util.sh
osh-native 96,114,769 5,160 test-cmd-util.sh
osh-nosouffle 112,207,085 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-9ace2075
osh-native osh-d9bf4118
osh-nosouffle osh-nosouffle-a5c38b48
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-19__06-14-20.cachegrind.tsv
no-host.2025-11-19__06-14-20.times.csv