I found a problematic sequence of a supposedly UTF-8 encoded text file. The strange thing is that grep seems unable to match this non-ASCII line.
$ iconv -f utf8 -t iso88591 corrupt_part.txt --output corrupt_part.txt.conv
iconv: illegal input sequence at position 8
$ cat corrupt_part.txt
Oberallg�u
$ grep -P -n '[^\x00-\x7F]' corrupt_part.txt
$ od -h corrupt_part.txt
0000000 624f 7265 6c61 676c 75e4 0a20
0000014
So \xe4
is e.g. ä
in the extended ASCII set. Yet, filtering on the control and printable characters (ascii range) the grep command above should match the \xe4
character. Why am I not getting any grep output?