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 11.1
osh-nosouffle 118,863 12.8

(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 2,610
bash 118,863 1,289
osh-native 118,863 509
osh-nosouffle 118,863 472
osh-cpython 118,863 10

Per-File Measurements

Time and Memory

shell label elapsed ms user ms sys ms max rss MB num lines filename
dash 2 1 1 2 2,698 Build.sh
bash 3 2 1 3 2,698 Build.sh
osh-native 7 4 3 9 2,698 Build.sh
osh-nosouffle 7 5 3 9 2,698 Build.sh
osh-cpython 321 300 21 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 3 2 1 3 2,512 abuild
osh-native 9 6 3 9 2,512 abuild
osh-nosouffle 9 8 1 9 2,512 abuild
osh-cpython 444 426 18 22 2,512 abuild
dash 9 9 0 2 20,489 configure
bash 17 16 1 4 20,489 configure
osh-native 37 26 11 23 20,489 configure
osh-nosouffle 40 32 8 23 20,489 configure
osh-cpython 2,094 2,053 40 44 20,489 configure
dash 23 23 0 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 126 103 23 52 69,779 configure-coreutils
osh-nosouffle 136 116 20 52 69,779 configure-coreutils
osh-cpython 6,051 5,976 72 91 69,779 configure-coreutils
bash 3 3 0 3 2,029 configure-helper.sh
osh-native 6 4 2 9 2,029 configure-helper.sh
osh-nosouffle 6 4 3 9 2,029 configure-helper.sh
osh-cpython 310 285 25 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 3 0 3 1,733 functions
osh-native 6 3 3 9 1,733 functions
osh-nosouffle 6 4 2 9 1,733 functions
osh-cpython 301 283 18 21 1,733 functions
dash 4 2 3 2 9,661 ltmain.sh
bash 9 8 1 4 9,661 ltmain.sh
osh-native 19 16 3 15 9,661 ltmain.sh
osh-nosouffle 20 11 9 16 9,661 ltmain.sh
osh-cpython 1,006 976 30 30 9,661 ltmain.sh
dash 1 0 1 1 1,679 t4014-format-patch.sh
bash 2 2 0 3 1,679 t4014-format-patch.sh
osh-native 4 1 3 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 3 1 8 1,679 t4014-format-patch.sh
osh-cpython 111 90 21 19 1,679 t4014-format-patch.sh
dash 1 0 1 1 3,123 t9300-fast-import.sh
bash 2 2 1 3 3,123 t9300-fast-import.sh
osh-native 4 3 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 3 1 8 3,123 t9300-fast-import.sh
osh-cpython 119 98 21 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 16 14 2 12 5,160 test-cmd-util.sh
osh-nosouffle 18 16 1 13 5,160 test-cmd-util.sh
osh-cpython 918 898 20 28 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 31,601,367 2,698 Build.sh
osh-nosouffle 35,849,615 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,723,943 2,512 abuild
osh-nosouffle 52,280,750 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,144,202 20,489 configure
osh-nosouffle 263,062,950 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,387,267 69,779 configure-coreutils
osh-nosouffle 862,832,546 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,987,956 2,029 configure-helper.sh
osh-nosouffle 30,266,182 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,471,830 1,733 functions
osh-nosouffle 28,861,286 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,275,369 9,661 ltmain.sh
osh-nosouffle 112,485,932 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,065,782 1,679 t4014-format-patch.sh
osh-nosouffle 11,040,644 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 11,870,205 3,123 t9300-fast-import.sh
osh-nosouffle 13,020,624 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 96,186,342 5,160 test-cmd-util.sh
osh-nosouffle 112,290,297 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-0ae8cc3a
osh-native osh-634aa08c
osh-nosouffle osh-nosouffle-00eb2946
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2026-01-14__03-21-04.cachegrind.tsv
no-host.2026-01-14__03-21-04.times.csv