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 2,597
bash 118,863 1,278
osh-nosouffle 118,863 429
osh-native 118,863 423
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 6 1 9 2,698 Build.sh
osh-nosouffle 8 4 4 9 2,698 Build.sh
osh-cpython 324 302 22 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 2 1 3 2,512 abuild
osh-native 9 7 2 9 2,512 abuild
osh-nosouffle 10 9 1 9 2,512 abuild
osh-cpython 464 439 25 23 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-nosouffle 42 30 12 23 20,489 configure
osh-native 43 36 7 22 20,489 configure
osh-cpython 2,138 2,093 45 45 20,489 configure
dash 23 23 0 2 69,779 configure-coreutils
bash 42 42 0 3 69,779 configure-coreutils
osh-nosouffle 154 133 21 52 69,779 configure-coreutils
osh-native 162 135 27 52 69,779 configure-coreutils
osh-cpython 6,294 6,188 101 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 7 3 3 9 2,029 configure-helper.sh
osh-nosouffle 7 6 1 9 2,029 configure-helper.sh
osh-cpython 325 306 19 22 2,029 configure-helper.sh
dash 1 1 1 2 1,733 functions
bash 3 1 2 3 1,733 functions
osh-native 6 4 3 8 1,733 functions
osh-nosouffle 7 4 2 9 1,733 functions
osh-cpython 305 280 25 22 1,733 functions
dash 4 4 1 2 9,661 ltmain.sh
bash 9 8 1 4 9,661 ltmain.sh
osh-native 21 16 4 15 9,661 ltmain.sh
osh-nosouffle 22 16 6 16 9,661 ltmain.sh
osh-cpython 1,020 986 34 30 9,661 ltmain.sh
dash 1 1 0 2 1,679 t4014-format-patch.sh
bash 2 1 1 3 1,679 t4014-format-patch.sh
osh-native 4 3 1 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 1 3 8 1,679 t4014-format-patch.sh
osh-cpython 119 104 16 20 1,679 t4014-format-patch.sh
dash 1 0 1 1 3,123 t9300-fast-import.sh
bash 2 1 1 3 3,123 t9300-fast-import.sh
osh-native 4 2 3 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 3 1 8 3,123 t9300-fast-import.sh
osh-cpython 121 102 19 20 3,123 t9300-fast-import.sh
bash 8 5 2 3 5,160 test-cmd-util.sh
osh-native 17 15 2 13 5,160 test-cmd-util.sh
osh-nosouffle 19 14 5 13 5,160 test-cmd-util.sh
osh-cpython 946 920 26 29 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 31,543,464 2,698 Build.sh
osh-nosouffle 35,793,406 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,683,648 2,512 abuild
osh-nosouffle 52,244,416 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,654,770 20,489 configure
osh-nosouffle 252,565,905 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,420,377 69,779 configure-coreutils
osh-nosouffle 836,752,343 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,954,629 2,029 configure-helper.sh
osh-nosouffle 30,232,535 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,440,501 1,733 functions
osh-nosouffle 28,830,181 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,138,760 9,661 ltmain.sh
osh-nosouffle 112,349,917 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,053,438 1,679 t4014-format-patch.sh
osh-nosouffle 11,028,639 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 11,858,242 3,123 t9300-fast-import.sh
osh-nosouffle 13,008,783 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 96,126,576 5,160 test-cmd-util.sh
osh-nosouffle 112,232,362 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-b6616b5f
osh-native osh-5372d9fd
osh-nosouffle osh-nosouffle-7e9d09b4
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-20__16-10-00.cachegrind.tsv
no-host.2025-11-20__16-10-00.times.csv