BASH shell error (STDERR) is displayed on the screen by default. For the following find command, all the output, including error is displayed on screen
find /var/lib/. -name “*.py”
bash$ find /var/lib/. -name "*.py*"
find: /var/lib/./zfs: Permission denied
find: /var/lib/./dav: Permission denied
find: /var/lib/./mlocate: Permission denied
find: /var/lib/./php/session: Permission denied
find: /var/lib/./ldap: Permission denied
find: /var/lib/./aide: Permission denied
find: /var/lib/./dovecot: Permission denied
find: /var/lib/./nvidia: Permission denied
find: /var/lib/./nfs/statd: Permission denied
find: /var/lib/./pgsql: Permission denied
find: /var/lib/./sss/pipes/private: Permission denied
find: /var/lib/./sss/db: Permission denied
find: /var/lib/./iptraf: Permission denied
/var/lib/./zope/bin/zopeservice.py
/var/lib/./zope/bin/zopeservice.pyo
/var/lib/./zope/bin/zopeservice.pyc
find: /var/lib/./imap: Permission denied
find: /var/lib/./mailman/archives/private: Permission denied
find: /var/lib/./dhcpv6: Permission denied
If the following command is used, it will only write out the ‘find’ result to the log file, not any error.
find /var/lib/. -name “*.py” > find_py.log
How can you log the error along with the output to a file so that you can read it later or from a remote session?
Follow the commands and output below
find /var/lib/. -name “*.py” > find_py.log
[Only STDOUT written to a log file; (STDERR output to screen only) ]
bash$ find /var/lib/. -name "*.py*" > find_py.log
find: /var/lib/./zfs: Permission denied
find: /var/lib/./dav: Permission denied
find: /var/lib/./mlocate: Permission denied
find: /var/lib/./php/session: Permission denied
find: /var/lib/./ldap: Permission denied
find: /var/lib/./aide: Permission denied
find: /var/lib/./dovecot: Permission denied
find: /var/lib/./nvidia: Permission denied
find: /var/lib/./nfs/statd: Permission denied
find: /var/lib/./pgsql: Permission denied
find: /var/lib/./sss/pipes/private: Permission denied
find: /var/lib/./sss/db: Permission denied
find: /var/lib/./iptraf: Permission denied
find: /var/lib/./imap: Permission denied
find: /var/lib/./mailman/archives/private: Permission denied
find: /var/lib/./dhcpv6: Permission denied
bash$ cat find_py.log
/var/lib/./zope/bin/zopeservice.py
/var/lib/./zope/bin/zopeservice.pyo
/var/lib/./zope/bin/zopeservice.pyc
find /var/lib/. -name “*.py” 2> find_py.log
[Only STDERR written to a log file; (No STDERR output to screen; Only STDOUT output on screen)]
bash$ find /var/lib/. -name "*.py*" 2> find_py.log
/var/lib/./zope/bin/zopeservice.py
/var/lib/./zope/bin/zopeservice.pyo
/var/lib/./zope/bin/zopeservice.pyc
bash$ cat find_py.log
find: /var/lib/./zfs: Permission denied
find: /var/lib/./dav: Permission denied
find: /var/lib/./mlocate: Permission denied
find: /var/lib/./php/session: Permission denied
find: /var/lib/./ldap: Permission denied
find: /var/lib/./aide: Permission denied
find: /var/lib/./dovecot: Permission denied
find: /var/lib/./nvidia: Permission denied
find: /var/lib/./nfs/statd: Permission denied
find: /var/lib/./pgsql: Permission denied
find: /var/lib/./sss/pipes/private: Permission denied
find: /var/lib/./sss/db: Permission denied
find: /var/lib/./iptraf: Permission denied
find: /var/lib/./imap: Permission denied
find: /var/lib/./mailman/archives/private: Permission denied
find: /var/lib/./dhcpv6: Permission denied
find /var/lib/. -name “*.py” 2> find_py.log 1>&2
STDOUT and STDERR written to a log file; (Nothing output to screen)
bash$ find /var/lib/. -name "*.py*" 2> find_py.log 1>&2
bash$ cat find_py.log
find: /var/lib/./zfs: Permission denied
find: /var/lib/./dav: Permission denied
find: /var/lib/./mlocate: Permission denied
find: /var/lib/./php/session: Permission denied
find: /var/lib/./ldap: Permission denied
find: /var/lib/./aide: Permission denied
find: /var/lib/./dovecot: Permission denied
find: /var/lib/./nvidia: Permission denied
find: /var/lib/./nfs/statd: Permission denied
find: /var/lib/./pgsql: Permission denied
find: /var/lib/./sss/pipes/private: Permission denied
find: /var/lib/./sss/db: Permission denied
find: /var/lib/./iptraf: Permission denied
/var/lib/./zope/bin/zopeservice.py
/var/lib/./zope/bin/zopeservice.pyo
/var/lib/./zope/bin/zopeservice.pyc
find: /var/lib/./imap: Permission denied
find: /var/lib/./mailman/archives/private: Permission denied
find: /var/lib/./dhcpv6: Permission denied
find /var/lib/. -name “*.py” 2>&1 | tee find_py_tee.log
STDOUT and STDERR written to a log file; (Also displayed on screen live while writing the log)
bash$ find /var/lib/. -name "*.py*" 2>&1 | tee find_py_tee.log
find: /var/lib/./zfs: Permission denied
find: /var/lib/./dav: Permission denied
find: /var/lib/./mlocate: Permission denied
find: /var/lib/./php/session: Permission denied
find: /var/lib/./ldap: Permission denied
find: /var/lib/./aide: Permission denied
find: /var/lib/./dovecot: Permission denied
find: /var/lib/./nvidia: Permission denied
find: /var/lib/./nfs/statd: Permission denied
find: /var/lib/./pgsql: Permission denied
find: /var/lib/./sss/pipes/private: Permission denied
find: /var/lib/./sss/db: Permission denied
find: /var/lib/./iptraf: Permission denied
/var/lib/./zope/bin/zopeservice.py
/var/lib/./zope/bin/zopeservice.pyo
/var/lib/./zope/bin/zopeservice.pyc
find: /var/lib/./imap: Permission denied
find: /var/lib/./mailman/archives/private: Permission denied
find: /var/lib/./dhcpv6: Permission denied
bash$ cat find_py_tee.log
find: /var/lib/./zfs: Permission denied
find: /var/lib/./dav: Permission denied
find: /var/lib/./mlocate: Permission denied
find: /var/lib/./php/session: Permission denied
find: /var/lib/./ldap: Permission denied
find: /var/lib/./aide: Permission denied
find: /var/lib/./dovecot: Permission denied
find: /var/lib/./nvidia: Permission denied
find: /var/lib/./nfs/statd: Permission denied
find: /var/lib/./pgsql: Permission denied
find: /var/lib/./sss/pipes/private: Permission denied
find: /var/lib/./sss/db: Permission denied
find: /var/lib/./iptraf: Permission denied
/var/lib/./zope/bin/zopeservice.py
/var/lib/./zope/bin/zopeservice.pyo
/var/lib/./zope/bin/zopeservice.pyc
find: /var/lib/./imap: Permission denied
find: /var/lib/./mailman/archives/private: Permission denied
find: /var/lib/./dhcpv6: Permission denied
The 2>&1 redirect STDERR to STDOUT.
This will record any errors to the logfile along with STDOUT.
