Collect multiple commands’ output to a single file

Syntax to run a few commands to gather some user / group ID info, as well as recursively list a folder’s contents and permissions all into a single file:

{ grep "^hadoop" /etc/group; id mapred; id hdfs; id mapred; id yarn; ls -ltrRa /var/log/hadoop-0.20-mapreduce/ } > /tmp/`hostname`-mr-info.txt


grep “^hadoop” /etc/group = list the accounts that are associated with the group hadoop
id mapred = display account ID info about the user mapred
id hdfs = display account ID info about the user hdfs
id yarn = display account ID info about the user yarn
ls -ltrRa /var/log/hadoop-0.20-mapreduce/ = Provide a recursive (-R) long list (-l)  of all (-a) directory and files from /var/log/hadoop-0.20-mapreduce, that’s sorted based on file timestamp (-t) in reverse order (-r)

{ ; } > /tmp/`hostname`-mr-info.txt  =   Run the commands first within the curly braces { }, then provide all the output to a file called (hostname of the machine)-mr-info.txt.  Important to have the final semicolon before terminating the end (right-most) curly brace otherwise a piping error will result.