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 3,245
bash 118,863 1,415
osh-native 118,863 519
osh-nosouffle 118,863 473
osh-cpython 118,863 11

Per-File Measurements

Time and Memory

shell label elapsed ms user ms sys ms max rss MB num lines filename
dash 1 1 0 2 2,698 Build.sh
bash 3 3 0 3 2,698 Build.sh
osh-native 7 4 3 9 2,698 Build.sh
osh-nosouffle 8 6 1 9 2,698 Build.sh
osh-cpython 280 265 16 22 2,698 Build.sh
dash 1 0 1 2 2,512 abuild
bash 3 3 0 3 2,512 abuild
osh-native 8 5 3 9 2,512 abuild
osh-nosouffle 9 8 1 9 2,512 abuild
osh-cpython 395 381 14 23 2,512 abuild
dash 7 6 1 2 20,489 configure
bash 16 15 1 4 20,489 configure
osh-native 36 24 12 22 20,489 configure
osh-nosouffle 40 27 14 23 20,489 configure
osh-cpython 1,871 1,844 27 44 20,489 configure
dash 18 18 0 2 69,779 configure-coreutils
bash 38 37 1 4 69,779 configure-coreutils
osh-native 126 114 11 52 69,779 configure-coreutils
osh-nosouffle 137 119 18 52 69,779 configure-coreutils
osh-cpython 5,426 5,380 45 91 69,779 configure-coreutils
bash 3 3 0 3 2,029 configure-helper.sh
osh-native 6 5 1 9 2,029 configure-helper.sh
osh-nosouffle 6 5 1 9 2,029 configure-helper.sh
osh-cpython 274 256 18 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 2 2 0 3 1,733 functions
osh-native 6 2 3 8 1,733 functions
osh-nosouffle 6 5 1 9 1,733 functions
osh-cpython 265 254 11 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 8 5 3 4 9,661 ltmain.sh
osh-native 18 14 4 16 9,661 ltmain.sh
osh-nosouffle 20 13 7 16 9,661 ltmain.sh
osh-cpython 886 862 23 30 9,661 ltmain.sh
dash 1 0 1 2 1,679 t4014-format-patch.sh
bash 2 1 1 3 1,679 t4014-format-patch.sh
osh-native 3 0 3 8 1,679 t4014-format-patch.sh
osh-nosouffle 4 0 4 8 1,679 t4014-format-patch.sh
osh-cpython 99 87 12 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 4 2 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 3 1 8 3,123 t9300-fast-import.sh
osh-cpython 105 94 11 19 3,123 t9300-fast-import.sh
bash 7 7 0 3 5,160 test-cmd-util.sh
osh-native 16 13 3 13 5,160 test-cmd-util.sh
osh-nosouffle 17 14 3 13 5,160 test-cmd-util.sh
osh-cpython 803 787 16 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 31,536,559 2,698 Build.sh
osh-nosouffle 35,785,807 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,675,377 2,512 abuild
osh-nosouffle 52,235,742 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,662,365 20,489 configure
osh-nosouffle 252,570,614 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,346,892 69,779 configure-coreutils
osh-nosouffle 836,675,842 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,949,734 2,029 configure-helper.sh
osh-nosouffle 30,227,001 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,432,233 1,733 functions
osh-nosouffle 28,821,560 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,149,639 9,661 ltmain.sh
osh-nosouffle 112,359,435 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,044,713 1,679 t4014-format-patch.sh
osh-nosouffle 11,019,337 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 11,850,051 3,123 t9300-fast-import.sh
osh-nosouffle 12,999,955 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 96,113,837 5,160 test-cmd-util.sh
osh-nosouffle 112,218,042 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-85fb5b2e
osh-native osh-dc89581d
osh-nosouffle osh-nosouffle-f824a6d4
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-19__05-15-23.cachegrind.tsv
no-host.2025-11-19__05-15-23.times.csv