I have just spent the last 3 hours trying to figure out why only ever 3rd file would upload (and then files would only randomly upload) and i continued to get UPLOAD_ERR_PARTIAL. It turns out UPLOAD_ERR_PARTIAL can be caused by the header Connection: Keep-Alive.
I wanted to search and replace every file in a directory tree and find a URL that linked to /web-design and remove that part of the URL, and i also wanted to find the phrase “Web Design” in a link and replace it with “Affordable Web Design”.
Usually i would have to go through each individual file via SSH or FTP and then open the file, make the edits, save the file and re-upload the file. The problem with that is, i needed to do this for over 15,000 files on over 3000 web sites, and that isn’t something i wanted to do.