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 12.8

(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 2,589
bash 118,863 1,242
osh-native 118,863 477
osh-nosouffle 118,863 436
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 3 0 3 2,698 Build.sh
osh-native 7 5 2 9 2,698 Build.sh
osh-nosouffle 8 5 3 9 2,698 Build.sh
osh-cpython 325 301 23 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-native 9 6 3 9 2,512 abuild
osh-nosouffle 10 7 3 9 2,512 abuild
osh-cpython 451 428 23 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 38 29 9 22 20,489 configure
osh-nosouffle 41 34 6 23 20,489 configure
osh-cpython 2,075 2,031 42 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 40 2 3 69,779 configure-coreutils
osh-native 139 119 19 52 69,779 configure-coreutils
osh-nosouffle 152 124 28 52 69,779 configure-coreutils
osh-cpython 6,242 6,171 71 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 6 2 4 9 2,029 configure-helper.sh
osh-nosouffle 7 5 2 9 2,029 configure-helper.sh
osh-cpython 317 296 21 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 3 3 8 1,733 functions
osh-nosouffle 7 5 2 9 1,733 functions
osh-cpython 303 280 23 21 1,733 functions
dash 5 3 1 2 9,661 ltmain.sh
bash 9 9 0 4 9,661 ltmain.sh
osh-native 19 12 7 15 9,661 ltmain.sh
osh-nosouffle 22 14 8 16 9,661 ltmain.sh
osh-cpython 1,011 975 36 30 9,661 ltmain.sh
dash 1 1 0 2 1,679 t4014-format-patch.sh
bash 3 1 1 3 1,679 t4014-format-patch.sh
osh-native 4 2 2 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 3 1 8 1,679 t4014-format-patch.sh
osh-cpython 112 95 17 19 1,679 t4014-format-patch.sh
dash 1 0 1 1 3,123 t9300-fast-import.sh
bash 2 2 1 3 3,123 t9300-fast-import.sh
osh-native 4 1 3 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 2 3 8 3,123 t9300-fast-import.sh
osh-cpython 119 99 20 19 3,123 t9300-fast-import.sh
bash 8 8 0 3 5,160 test-cmd-util.sh
osh-native 17 12 5 12 5,160 test-cmd-util.sh
osh-nosouffle 19 14 5 13 5,160 test-cmd-util.sh
osh-cpython 915 891 24 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 31,601,388 2,698 Build.sh
osh-nosouffle 35,849,656 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,723,964 2,512 abuild
osh-nosouffle 52,280,791 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,144,223 20,489 configure
osh-nosouffle 263,062,937 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,387,287 69,779 configure-coreutils
osh-nosouffle 862,832,533 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,987,976 2,029 configure-helper.sh
osh-nosouffle 30,266,196 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,471,851 1,733 functions
osh-nosouffle 28,861,300 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,275,390 9,661 ltmain.sh
osh-nosouffle 112,485,946 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,065,796 1,679 t4014-format-patch.sh
osh-nosouffle 11,040,658 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 11,870,219 3,123 t9300-fast-import.sh
osh-nosouffle 13,020,638 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 96,186,362 5,160 test-cmd-util.sh
osh-nosouffle 112,290,283 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-bcba5b83
osh-native osh-d196cf0e
osh-nosouffle osh-nosouffle-5a7e7cc2
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2026-01-20__16-36-08.cachegrind.tsv
no-host.2026-01-20__16-36-08.times.csv