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 2,589
bash 118,863 1,267
osh-native 118,863 470
osh-nosouffle 118,863 435
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 1 2 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
osh-cpython 322 295 27 22 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-nosouffle 9 7 2 9 2,512 abuild
osh-native 16 12 4 9 2,512 abuild
osh-cpython 447 424 23 22 2,512 abuild
dash 9 7 2 2 20,489 configure
bash 17 17 0 4 20,489 configure
osh-native 38 31 7 23 20,489 configure
osh-nosouffle 41 33 9 23 20,489 configure
osh-cpython 2,128 2,083 44 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 135 107 28 52 69,779 configure-coreutils
osh-nosouffle 155 131 24 52 69,779 configure-coreutils
osh-cpython 6,107 6,036 71 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 6 3 3 9 2,029 configure-helper.sh
osh-nosouffle 7 2 5 9 2,029 configure-helper.sh
osh-cpython 311 290 21 21 2,029 configure-helper.sh
dash 1 0 1 1 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 3 3 9 1,733 functions
osh-nosouffle 7 5 2 9 1,733 functions
osh-cpython 309 286 23 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 9 7 2 4 9,661 ltmain.sh
osh-native 20 13 7 16 9,661 ltmain.sh
osh-nosouffle 20 15 6 16 9,661 ltmain.sh
osh-cpython 1,011 982 29 30 9,661 ltmain.sh
dash 1 0 1 2 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 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 112 98 15 19 1,679 t4014-format-patch.sh
dash 1 1 1 1 3,123 t9300-fast-import.sh
bash 3 1 1 3 3,123 t9300-fast-import.sh
osh-native 4 3 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 2 2 8 3,123 t9300-fast-import.sh
osh-cpython 119 102 18 19 3,123 t9300-fast-import.sh
bash 8 8 0 3 5,160 test-cmd-util.sh
osh-native 17 14 3 13 5,160 test-cmd-util.sh
osh-nosouffle 18 15 3 13 5,160 test-cmd-util.sh
osh-cpython 909 879 30 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 31,601,416 2,698 Build.sh
osh-nosouffle 35,849,685 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,723,992 2,512 abuild
osh-nosouffle 52,280,820 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,144,251 20,489 configure
osh-nosouffle 263,062,966 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,387,315 69,779 configure-coreutils
osh-nosouffle 862,832,562 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,988,004 2,029 configure-helper.sh
osh-nosouffle 30,266,225 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,471,879 1,733 functions
osh-nosouffle 28,861,329 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,275,418 9,661 ltmain.sh
osh-nosouffle 112,485,975 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,065,824 1,679 t4014-format-patch.sh
osh-nosouffle 11,040,687 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 11,870,247 3,123 t9300-fast-import.sh
osh-nosouffle 13,020,667 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 96,186,390 5,160 test-cmd-util.sh
osh-nosouffle 112,290,312 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-0c6db79f
osh-native osh-fb32cb5f
osh-nosouffle osh-nosouffle-ba70cbdf
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2026-01-25__21-04-07.cachegrind.tsv
no-host.2026-01-25__21-04-07.times.csv