If I run apt-cache show nonexistent
, I get this error:
N: Unable to locate package nonexistent
E: No packages found
I know the E stands for "Error", and a W would stand for "Warning", but what does the N stand for? "Information"?
Are there other letters that may show up?
I couldn't find anything in man apt-cache
, man apt
, or man apt-get
.
P.s. This came up because of this question: Bash file redirection bug?
Letters designate error message type. By looking at the
apt-cache
C++ source code and the relatederror.cc
file, there's apparently different types of errors:GEMessage(FatalE, FATAL)
GEMessage(Errno, ERROR)
GEMessage(WarningE, WARNING)
GEMessage(NoticeE, NOTICE)
GEMessage(DebugE, DEBUG)
The errors are pushed onto message stack via
_error->Insert
method which in the apt-cache source is apparently an "alias" forGlobalError::Insert
method.Interestingly enough there's also CacheSetHelper which sets whether to show errors or not. That defaults to showing errors in the constructor for this class, and message type to ERROR.