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 2,580
bash 118,863 1,276
osh-native 118,863 480
osh-nosouffle 118,863 456
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 2 0 2 2,698 Build.sh
bash 3 2 1 3 2,698 Build.sh
osh-native 7 5 2 9 2,698 Build.sh
osh-nosouffle 7 7 0 9 2,698 Build.sh
osh-cpython 326 306 20 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 2 1 3 2,512 abuild
osh-native 9 5 4 9 2,512 abuild
osh-nosouffle 9 7 2 9 2,512 abuild
osh-cpython 453 436 17 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 38 30 8 22 20,489 configure
osh-nosouffle 41 32 9 23 20,489 configure
osh-cpython 2,175 2,133 43 44 20,489 configure
dash 23 21 2 2 69,779 configure-coreutils
bash 42 42 0 4 69,779 configure-coreutils
osh-native 139 119 20 52 69,779 configure-coreutils
osh-nosouffle 143 123 20 52 69,779 configure-coreutils
osh-cpython 6,325 6,256 68 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 6 5 1 9 2,029 configure-helper.sh
osh-nosouffle 7 3 3 9 2,029 configure-helper.sh
osh-cpython 315 292 23 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 4 2 8 1,733 functions
osh-nosouffle 6 4 3 9 1,733 functions
osh-cpython 310 290 20 21 1,733 functions
dash 4 2 3 2 9,661 ltmain.sh
bash 9 7 2 4 9,661 ltmain.sh
osh-native 19 13 6 15 9,661 ltmain.sh
osh-nosouffle 20 15 5 16 9,661 ltmain.sh
osh-cpython 1,019 987 32 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 114 95 20 19 1,679 t4014-format-patch.sh
dash 1 1 0 2 3,123 t9300-fast-import.sh
bash 2 1 1 3 3,123 t9300-fast-import.sh
osh-native 4 1 3 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 2 2 8 3,123 t9300-fast-import.sh
osh-cpython 119 105 15 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 16 12 4 13 5,160 test-cmd-util.sh
osh-nosouffle 18 13 5 13 5,160 test-cmd-util.sh
osh-cpython 926 899 28 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 31,593,805 2,698 Build.sh
osh-nosouffle 35,841,504 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,711,031 2,512 abuild
osh-nosouffle 52,275,868 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,134,084 20,489 configure
osh-nosouffle 263,045,573 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,366,705 69,779 configure-coreutils
osh-nosouffle 837,521,081 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,982,509 2,029 configure-helper.sh
osh-nosouffle 30,260,637 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,467,813 1,733 functions
osh-nosouffle 28,857,228 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,270,415 9,661 ltmain.sh
osh-nosouffle 112,480,613 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,061,575 1,679 t4014-format-patch.sh
osh-nosouffle 11,036,475 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 11,866,028 3,123 t9300-fast-import.sh
osh-nosouffle 13,016,303 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 96,174,024 5,160 test-cmd-util.sh
osh-nosouffle 112,280,739 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-9ec2f67d
osh-native osh-52d43f0f
osh-nosouffle osh-nosouffle-e842ad2f
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-07__11-31-30.cachegrind.tsv
no-host.2025-12-07__11-31-30.times.csv