Control: reopen 848849 > It is really hard from a pipe to guess the type of file.
Huh? It has been possible and has been working fine (from user POV) for years. Even the oldest version I can access right now (Ubuntu 14) works this way. And if this is a deliberately introduced regression then I expect you to announce such things via the NEWS file. > XWD magic is only 3 bytes and better error handling need seek that are not > available on pipe (stdin). This is not really an explanation. Are you trying to say that previously they did the detection in later stages when more data was available and now this happens in the beginning, within the first read package or something? In which case... why not increase the size of the first read package to get enough data? > Using file more information could be given using file extension. Huh? There is no suffix, it's a stream. You probably mean "-format xwd"? But even that workaround is broken: $ xwd -root | convert -format xwd - deleteme.png convert-im6.q16: no decode delegate for this image format `' @ error/constitute.c/ReadImage/504. convert-im6.q16: no images defined `deleteme.png' @ error/convert.c/ConvertImageCommand/3258. And this also was ok with older version. Regards, Eduard.