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awk -F| BEGIN{ initialization } { code block } END{ finalization } — general syntax
default delimiter is space
VAR=«value» — define a variable
print VAR — print a variable
NF is number of fields
$NF is value of last field
print "$EXTERNAL_VAR" — double single $EXTERNAL_VAR single double
VAR~/pattern/ — pattern patching
VAR!~/pattern/ — does not match
FS returns value of field separator, same as -F
OFS returns output field separator
print $1,$2 is separated
NR returns line number
FILENAME returns current filename
awk -v var1=value1 — pre-assign values to variables in awk
awk -F, conditions { code block } filename — condition must be right before code block

cut — get columns from file
cut -d, -f1-2 filename — print 1st to 2nd columns
cut -c1-5 filename — print first 5 characters
cut -d, -f2- filename — print from 2nd column to last column
cut -d, -f1,4,5 filename — print 1st, 4th and 5th column
cut -d, -f-3 filename — print from 1st to 3rd column
cut -d, -f1,3-5 filename — print 1st, 3rd to 5th column

wc — word count
wc -l — line count
wc -c — print number of bytes
wc — print number of newline, word and bytes
wc -m — character count
wc -w — word count

last — check login history
last -10 — show last 10 logins
last -F — show full login information