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 118,863 11.0
osh-nosouffle 118,863 12.5

(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 3,284
bash 118,863 1,440
osh-native 118,863 550
osh-nosouffle 118,863 502
osh-cpython 118,863 12

Per-File Measurements

Time and Memory

shell label elapsed ms user ms sys ms max rss MB num lines filename
dash 1 0 1 2 2,698 Build.sh
bash 3 3 0 3 2,698 Build.sh
osh-native 6 5 1 9 2,698 Build.sh
osh-nosouffle 7 6 1 9 2,698 Build.sh
osh-cpython 279 262 17 22 2,698 Build.sh
dash 1 1 1 2 2,512 abuild
bash 3 3 0 3 2,512 abuild
osh-native 8 6 2 9 2,512 abuild
osh-nosouffle 9 7 2 9 2,512 abuild
osh-cpython 391 373 18 22 2,512 abuild
dash 7 6 1 2 20,489 configure
bash 15 12 3 4 20,489 configure
osh-native 35 31 4 23 20,489 configure
osh-nosouffle 39 28 11 23 20,489 configure
osh-cpython 1,856 1,830 25 44 20,489 configure
dash 18 18 0 2 69,779 configure-coreutils
bash 38 37 1 4 69,779 configure-coreutils
osh-native 118 96 22 52 69,779 configure-coreutils
osh-nosouffle 127 106 21 52 69,779 configure-coreutils
osh-cpython 5,329 5,268 57 91 69,779 configure-coreutils
bash 3 1 2 3 2,029 configure-helper.sh
osh-native 5 4 1 9 2,029 configure-helper.sh
osh-nosouffle 6 3 3 9 2,029 configure-helper.sh
osh-cpython 273 258 14 22 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 2 2 0 3 1,733 functions
osh-native 5 3 2 8 1,733 functions
osh-nosouffle 6 4 2 9 1,733 functions
osh-cpython 263 252 11 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 8 8 0 4 9,661 ltmain.sh
osh-native 17 14 3 16 9,661 ltmain.sh
osh-nosouffle 19 14 5 16 9,661 ltmain.sh
osh-cpython 888 871 17 30 9,661 ltmain.sh
dash 1 0 1 2 1,679 t4014-format-patch.sh
bash 2 0 2 3 1,679 t4014-format-patch.sh
osh-native 3 3 0 8 1,679 t4014-format-patch.sh
osh-nosouffle 3 2 1 8 1,679 t4014-format-patch.sh
osh-cpython 96 83 13 19 1,679 t4014-format-patch.sh
dash 1 1 0 2 3,123 t9300-fast-import.sh
bash 2 2 0 3 3,123 t9300-fast-import.sh
osh-native 3 1 2 8 3,123 t9300-fast-import.sh
osh-nosouffle 3 2 1 8 3,123 t9300-fast-import.sh
osh-cpython 102 88 14 19 3,123 t9300-fast-import.sh
bash 7 5 2 3 5,160 test-cmd-util.sh
osh-native 15 13 2 12 5,160 test-cmd-util.sh
osh-nosouffle 17 13 4 13 5,160 test-cmd-util.sh
osh-cpython 804 786 18 29 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 31,535,706 2,698 Build.sh
osh-nosouffle 35,785,347 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,675,890 2,512 abuild
osh-nosouffle 52,236,357 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,647,012 20,489 configure
osh-nosouffle 252,557,819 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,412,619 69,779 configure-coreutils
osh-nosouffle 836,744,251 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,946,871 2,029 configure-helper.sh
osh-nosouffle 30,224,470 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,432,743 1,733 functions
osh-nosouffle 28,822,122 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,131,002 9,661 ltmain.sh
osh-nosouffle 112,341,831 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,045,680 1,679 t4014-format-patch.sh
osh-nosouffle 11,020,580 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 11,850,484 3,123 t9300-fast-import.sh
osh-nosouffle 13,000,724 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 96,119,062 5,160 test-cmd-util.sh
osh-nosouffle 112,224,601 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-126c98b4
osh-native osh-6784c099
osh-nosouffle osh-nosouffle-43683009
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-22__17-09-24.cachegrind.tsv
no-host.2025-11-22__17-09-24.times.csv