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 10.8
osh-nosouffle 118,863 12.3

(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 2,601
bash 118,863 1,278
osh-native 118,863 451
osh-nosouffle 118,863 424
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 9 5 4 9 2,698 Build.sh
osh-nosouffle 10 6 4 10 2,698 Build.sh
osh-cpython 321 291 30 22 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 4 2 1 3 2,512 abuild
osh-native 11 7 4 9 2,512 abuild
osh-nosouffle 12 6 6 10 2,512 abuild
osh-cpython 451 426 25 22 2,512 abuild
dash 9 9 0 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 41 29 12 23 20,489 configure
osh-nosouffle 43 31 12 23 20,489 configure
osh-cpython 2,130 2,092 35 44 20,489 configure
dash 23 23 0 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 137 115 22 52 69,779 configure-coreutils
osh-nosouffle 144 117 27 53 69,779 configure-coreutils
osh-cpython 6,240 6,153 86 90 69,779 configure-coreutils
bash 3 2 2 3 2,029 configure-helper.sh
osh-native 8 5 3 9 2,029 configure-helper.sh
osh-nosouffle 8 5 3 10 2,029 configure-helper.sh
osh-cpython 320 297 24 21 2,029 configure-helper.sh
dash 1 0 1 2 1,733 functions
bash 3 1 1 3 1,733 functions
osh-native 8 5 3 9 1,733 functions
osh-nosouffle 8 3 5 9 1,733 functions
osh-cpython 305 285 20 21 1,733 functions
dash 4 2 2 2 9,661 ltmain.sh
bash 9 8 1 4 9,661 ltmain.sh
osh-native 20 14 6 16 9,661 ltmain.sh
osh-nosouffle 22 17 5 17 9,661 ltmain.sh
osh-cpython 1,004 968 37 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 5 1 4 8 1,679 t4014-format-patch.sh
osh-nosouffle 5 1 4 9 1,679 t4014-format-patch.sh
osh-cpython 111 89 23 19 1,679 t4014-format-patch.sh
dash 1 1 1 1 3,123 t9300-fast-import.sh
bash 2 2 0 3 3,123 t9300-fast-import.sh
osh-native 6 3 3 8 3,123 t9300-fast-import.sh
osh-nosouffle 6 3 4 9 3,123 t9300-fast-import.sh
osh-cpython 118 99 20 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 18 13 6 13 5,160 test-cmd-util.sh
osh-nosouffle 21 18 4 14 5,160 test-cmd-util.sh
osh-cpython 913 885 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 31,522,489 2,698 Build.sh
osh-nosouffle 35,770,594 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,693,038 2,512 abuild
osh-nosouffle 52,259,096 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 216,235,010 20,489 configure
osh-nosouffle 248,144,837 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 731,107,537 69,779 configure-coreutils
osh-nosouffle 820,453,129 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 26,040,405 2,029 configure-helper.sh
osh-nosouffle 30,317,497 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,610,039 1,733 functions
osh-nosouffle 28,999,015 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 94,347,969 9,661 ltmain.sh
osh-nosouffle 110,556,936 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,233,116 1,679 t4014-format-patch.sh
bash 11,082,677 1,679 t4014-format-patch.sh
osh-nosouffle 11,207,634 1,679 t4014-format-patch.sh
dash 4,585,030 3,123 t9300-fast-import.sh
osh-native 11,744,156 3,123 t9300-fast-import.sh
osh-nosouffle 12,894,014 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 95,314,602 5,160 test-cmd-util.sh
osh-nosouffle 111,415,150 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-67cbbe29
osh-native osh-6bcf32ba
osh-nosouffle osh-nosouffle-1edc6daa
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-19__19-24-32.cachegrind.tsv
no-host.2025-11-19__19-24-32.times.csv