% sha1sum -c KNOPPIX_V5.1.1CD-2007-01-04-EN.iso.sha1.asc 
KNOPPIX_V5.1.1CD-2007-01-04-EN.iso: OK
% 
% sha1sum -c KNOPPIX_V5.1.1CD-2007-01-04-EN.iso.sha1.asc KNOPPIX_V5.1.1CD-2007-01-04-EN.iso
KNOPPIX_V5.1.1CD-2007-01-04-EN.iso: OK
sha1sum: COM : No such file or directory
COM : FAILED open or read
sha1sum: ÛÞ^AEÍÞÚnÃó¨â²]Rßlh®\xÑ-n©uRX¯¯HY[®.¬0¡²uôùÙ¬£¶ê¶eîW«í¥W+À
YçóÄ6îÎoe'ç´ßJ}íÞ4ê=Æðº
                       ë}<ÓàÚUw{y+^[[?1;2c: No such file or directory
ÛÞ^AEÍÞÚnÃó¨â²]Rßlh®\xÑ-n©uRX¯¯HY[®.¬0¡²uôùÙ¬£¶ê¶eîW«í¥W+À
YçóÄ6îÎoe'ç´ßJ}íÞ4ê=Æðº
                       ë}<ÓàÚUw{y+: FAILED open or read
^[[?1;2csha1sum: WARNING: 2 of 2 listed files could not be read