diff --git a/tests/diff/README.md b/tests/diff/README.md index 34c2210..63bfa10 100644 --- a/tests/diff/README.md +++ b/tests/diff/README.md @@ -1,15 +1,17 @@ -`comparediffs` provides a tools for downloading a PDF from two different sources, running pdfparanoia on the files, comparing the outputs byte-for-byte, -and reporting the results. +`comparediffs` provides a tool which +* downloads a PDF from two different sources, +* runs `pdfparanoia` on both files, and +* compares the outputs byte-for-byte. Typical usage is to first establish two `ssh` tunnels to hosts with access to the literature, e.g. via `ssh -D 1080 host1` and `ssh -D 1081 host2`. You can then invoke `comparediffs` via ./comparediffs localhost:1080 localhost:1081 < urls -where urls is a file containing one URL per line (e.g. the example file in this directory). +where `urls` is a file containing one URL per line (e.g. the example file in this directory). -`comparediffs` creates a subdirectory `pdf/`, in which is stores PDFs. It won't try to download the same PDF twice, so if you fix pdfparanoia you'll -need to clean out some or all of this subdirectory. +`comparediffs` creates a subdirectory `pdf/`, in which is stores PDFs. It won't try to download the same PDF twice, so if you make changes to `pdfparanoia` you'll +want to clean out some or all of this subdirectory. -It's easy to see which PDFs pdfparanoia failed on, as it leaves copies of the scrubbed files with suffixes `.1.cleaned.pdf` and `.2.cleaned.pdf`. -When pdfparanoia succeeds (or isn't even needed, because the downloaded files were identical), the scrubbed files are removed. +It's easy to see which PDFs `pdfparanoia` failed on afterwards, as it leaves copies of the scrubbed files with suffixes `.1.cleaned.pdf` and `.2.cleaned.pdf`. +When `pdfparanoia` succeeds (or isn't even needed, because the downloaded files were identical), the scrubbed files are removed.