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 12.6

(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 2,535
bash 118,863 1,240
osh-native 118,863 369
osh-nosouffle 118,863 329
osh-cpython 118,863 9

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 3 0 3 2,698 Build.sh
osh-native 8 5 4 8 2,698 Build.sh
osh-nosouffle 9 7 3 9 2,698 Build.sh
osh-cpython 338 316 22 21 2,698 Build.sh
dash 2 1 1 1 2,512 abuild
bash 4 4 0 3 2,512 abuild
osh-native 10 7 3 9 2,512 abuild
osh-nosouffle 12 11 1 9 2,512 abuild
osh-cpython 468 443 25 22 2,512 abuild
dash 9 9 0 2 20,489 configure
bash 18 17 1 4 20,489 configure
osh-native 47 38 9 22 20,489 configure
osh-nosouffle 51 44 7 23 20,489 configure
osh-cpython 2,298 2,253 43 44 20,489 configure
dash 23 23 0 2 69,779 configure-coreutils
bash 43 41 2 3 69,779 configure-coreutils
osh-native 195 169 26 52 69,779 configure-coreutils
osh-nosouffle 210 189 21 52 69,779 configure-coreutils
osh-cpython 6,861 6,765 96 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-nosouffle 8 4 4 9 2,029 configure-helper.sh
osh-native 8 4 4 9 2,029 configure-helper.sh
osh-cpython 336 310 26 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 1 2 3 1,733 functions
osh-native 7 3 4 9 1,733 functions
osh-nosouffle 8 7 1 9 1,733 functions
osh-cpython 324 304 20 21 1,733 functions
dash 4 5 0 2 9,661 ltmain.sh
bash 10 10 0 4 9,661 ltmain.sh
osh-native 20 13 7 16 9,661 ltmain.sh
osh-nosouffle 31 22 9 16 9,661 ltmain.sh
osh-cpython 1,083 1,053 30 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 5 2 3 7 1,679 t4014-format-patch.sh
osh-nosouffle 5 3 2 8 1,679 t4014-format-patch.sh
osh-cpython 123 105 18 19 1,679 t4014-format-patch.sh
dash 1 1 1 1 3,123 t9300-fast-import.sh
bash 3 3 0 3 3,123 t9300-fast-import.sh
osh-native 5 2 3 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 1 4 8 3,123 t9300-fast-import.sh
osh-cpython 130 109 21 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 18 10 8 12 5,160 test-cmd-util.sh
osh-nosouffle 23 16 7 13 5,160 test-cmd-util.sh
osh-cpython 980 937 43 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 31,595,712 2,698 Build.sh
osh-nosouffle 35,843,397 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,713,583 2,512 abuild
osh-nosouffle 52,278,435 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,139,807 20,489 configure
osh-nosouffle 263,051,961 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,356,348 69,779 configure-coreutils
osh-nosouffle 837,536,106 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,983,701 2,029 configure-helper.sh
osh-nosouffle 30,261,699 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,469,008 1,733 functions
osh-nosouffle 28,858,421 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,272,738 9,661 ltmain.sh
osh-nosouffle 112,483,402 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,062,134 1,679 t4014-format-patch.sh
osh-nosouffle 11,036,979 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 11,866,584 3,123 t9300-fast-import.sh
osh-nosouffle 13,016,773 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 96,177,403 5,160 test-cmd-util.sh
osh-nosouffle 112,284,725 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-aa0f41b8
osh-native osh-7971bf79
osh-nosouffle osh-nosouffle-cdc6483e
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-08__19-18-36.cachegrind.tsv
no-host.2025-12-08__19-18-36.times.csv