File paths with spaces cause early command splitting on Windows CMD

[jonnyawsom3]

'Solid' file path.

hyperfine -r 1 --show-output -i "djxl "C:\Users\jonat\Downloads\Test.jxl" --disable_output"
Benchmark 1: djxl C:\Users\jonat\Downloads\Test.jxl --disable_output
JPEG XL decoder v0.12.0 3d7cec2 [AVX2,SSE2]
Decoded to pixels.
4100 x 4000,  98.436 MP/s [98.44, 98.44], , 1 reps, 16 threads.
  Time (abs ≡):        210.1 ms               [User: 1951.6 ms, System: 275.0 ms]

With a single space.

hyperfine -r 1 --show-output -i "djxl "C:\Users\jonat\Downloads\Te st.jxl" --disable_output"
Benchmark 1: djxl C:\Users\jonat\Downloads\Te
JPEG XL decoder v0.12.0 3d7cec2 [AVX2,SSE2]
couldn't load C:\Users\jonat\Downloads\Te
  Time (abs ≡):         15.7 ms               [User: 0.0 ms, System: 9.1 ms]

  Warning: Ignoring non-zero exit code.

Benchmark 2: st.jxl --disable_output
'st.jxl' is not recognized as an internal or external command,
operable program or batch file.
  Time (abs ≡):         11.5 ms               [User: 0.0 ms, System: 0.0 ms]

  Warning: Ignoring non-zero exit code.

Summary
  st.jxl --disable_output ran
    1.37 times faster than djxl C:\Users\jonat\Downloads\Te

The file path is split into separate commands with every additional space, making it quite hard to benchmark files without first moving and renaming them.

[leno23]

Thanks for the report. The output showing two benchmarks (djxl …\Te and st.jxl --disable_output) usually means cmd.exe split the hyperfine invocation into multiple positional command arguments before hyperfine runs anything — not that hyperfine re-split a single command when calling cmd /C.

On Windows CMD, nested quotes are easy to get wrong. For a path with spaces, pass the whole benchmark as one argument (after --):

hyperfine -r 1 --show-output --ignore-failure -- "djxl \"C:\Users\jonat\Downloads\Te st.jxl\" --disable_output"

In PowerShell, quoting rules differ and often work more predictably for this case.

If you still see a single benchmark name but the executed command is truncated at the first space (with correct quoting on the hyperfine CLI), please post that minimal repro — that would point at a different bug in how we pass the line to cmd /C (related to, but distinct from, #818 / #876).

Workaround: --shell=none with a properly quoted command line, or run from PowerShell.

[jonnyawsom3]

Interesting, I never found any mention of \" for the file path, but it seems to work. Thank you for figuring it out.