I'm developing a web application which downloads a number of web pages using PHP curl. It then uses
diff to compare the files as they change each day.
I reported a problem a few weeks back where seemingly identical files were being flagged by
diff as being different: https://stackoverflow.com/questions/42552239/different-versions-of-diff-giving-mixed-results-when-comparing-2-identical-fil
The answer to the above was that if
diff was used with the
-w flag it ignores whitespace.
However, I've now noticed a separate problem. If I download one of the files I'm comparing, and re-upload (overwrite) it through an FTP client, the output changes.
For example: Compare
diff file1.html file2.html it may give output such as
12159,12161c12159,12161 < < < --- > > > 12163,12172c12163,12172 < < < < < < < < < < ---
However, if I download
file2.html to my desktop and re-upload it through FTP,
diff without the
-w flag reports there being no differences at all i.e. it's now saying the files are identical.
I've tried to check the encoding of the file using
file -bi file2.html but it's reported the same before and after upload through FTP. The encoding is
If the encoding is no different and the file contents have not been modified, how is re-uploading the file through FTP changing anything?? I've tried it using FileZilla and also through Netbeans.
I'm using macOS Sierra locally and the remote server is Apache 2/PHP 7/centOS.