#Cat/Tac Concatenates and writes files cat [options] FILE Cat copies a file contents and pipes to standard output. It also can copy standard output to a file
Flags: -A, --show-all
-b, -number-nonblank (Number of nonempty lines in file)
-E,--show-ends (Shows a $ after the end of each line)
-n, --number (number of all lines outputted, ommited if -b is present)
-s,--squeeze-blank (Supresses number of empty lines)
-T,--show-tabs (Displays TAB characters as '^I'
-v, --show-nonprinting (Displays controls characters using '^' notation)
Shortcuts: -t (Same as '-vT') -e (Same as '-vE') -A (Same as '-vET')
#Example: //Redirects f contents to stdio and then into g cat f - g
tac [options] FILE Same as cat except in Reverse
-b,--before (Separator is attached before redirecting stdio to file
-r,--regex (treats Separator string as regex -s SEPARATOR,--separator=SEPARATOR (Uses separator as line separator instead of \n)
#Example //reverse file contents character by character
'tac -r -s 'x|[^x]'
#Where to find this
info cat invocation