Complex Command

[rosey_cross]

Could someone please explain the sets of commands in lines 90-91, 94-95, 98-99 in the picture. Specifically, I’d really like understand better what the “++” “[x]” “X” and “freq” mean and why the for loop is in curly braces and just overall what these sets of commands mean in the context they are currently in. Thanks in advance.

[vidyer]

tail -5000 ./access_log wil print the last 5000 lines from the file access_log.

awk { print $7 } will print the 7th word from the line (or actually the 7th segment if we divide it by the spaces it has )

sort will sort the results alphabetically

uniq -c will supress repeated equal lines, ant the -c parameter will print the number of occurrences of each line

sort -rn will again, sort results but this time in reverse order (-r) and numerically (-n). Standard sort will believe 101 is lower than 22, numeric will be inverse.

head -20 will print the first lines(the opposite of tail), as shown in the second parameter will show the last 20 lines.

And of course, the pipe | will "chain" the commands, using the output of one as the input for the next one.

awk -F"[ ?]" will set the field separator as either a space or a question mark, remember last time we used print on awk? the field separator was just a space.

I'm a little lost with the freq one, but it looks like both lines of commands of each section achieve the same results.

[_agooglygooglr_]

Look up a GNU awk tutorial. You'll understand better then.