1.003: How do I get rid of the verbose error messages?

Many of the messages from the Unix commands are available in different
languages. This is controlled by the LANG environment variable, the
default being En_US meaning English in the US. All the default messages
have a message number associated with them, e.g.:

$ cat no-such-file
cat: 0652-050 Cannot open no-such-file.

If you prefer the terser Unix-looking error message, set your
environment variable LC_MESSAGES to C, and you will get:

$ cat no-such-file
cat: Cannot open no-such-file.

By default LC_MESSAGES is the same as your environment LANG.  Setting
LANG does also work, but should be avoided since it changes
app-defaults lookup etc.  See locale(): LC_ALL