linux-readonly-view-text-cat-more-less-tail-head
cat -b filename
//above is line numbers but below is line numbers on blank lines too
cat -n filename
cat -A //shows whitespace non printable characters too
"more", q to quit, spacebar to advance a screen, enter to advance a line, no going back arrow keys to move around
more +10 //starts at line# 10
more /"string" //only shows lines with the given text
"less", q to quit, spacebar wholescreen, d halfscreen, b backscreen, u halfbackscreen
less z10 //enter = forward ten lines instead of one line, y10 would be back
-V highlights tabs, line endings, non printable characters
ctl+k highlights all string instances from less /"string", esc+u unhighlights
-I = case insensitive search
:n and :p = multi-file navigation
"head" /var/log/filename.log shows the top 10 lines, head -20 shows 20 lines
"tail" -v shows the file name/format, -f shows the file as new output is added
tail -f -s 5 //will check every 5 seconds for new output, --pid means -f depends on a process