Working with the Unix OS

Unix Tools
# print last input line
{ last = $0 }
END { print last }
# counting lines, words and characters
{ nc = nc + length($0) + 1
nw = nw + NF
}
END { print NR, "lines,", nw, "words,", nc, "characters" }
! Flow Control
# compute total & average pay of employees above $6/hour
$2 > 6 { n = n + 1; pay = pay + $2 * $3 }
END {
if (n > 0)
print n, "employees, total pay is", pay, "average is", pay/n
else
print "no employees are paid more than $6/hour"
}
# interest1 – compute compound interest
# input: amount rate years
# output: compounded value at end of each year
{ i = 1
while (i 4
# Print all input lines where last field is greater than 4
$NF > 4
# Print the total number of fields in all input lines
{ nf = nf + NF }
END {print nf}
# Print the total number of lines that contain Mark
/Mark/ { nlines = nlines + 1 }
END {print nlines}
# Print the largest field first and line that contains it
$1 > max { max = $1; maxline = $0 }