z/OS V1R9.0 UNIX System Services Command ... - Christian Grothoff

awk
{print NR ":" $0}
3. The following program appends all input lines starting with January to the file
jan (which may or may not exist already), and all lines starting with February
or March to the file febmar:
/^January/ {print >> "jan"}
/^February|^March/ {print >> "febmar"}
4. This program prints the total and average for the last column of each input
line:
{s += $NF}
END {print "sum is", s, "average is", s/NR}
5. The next program interchanges the first and second fields of input lines:
{
}
tmp = $1
$1 = $2
$2 = tmp
print
6. The following inserts line numbers so that output lines are left-aligned:
{printf "%–6d: %s\n", NR, $0}
7. The following prints input records in reverse order (assuming sufficient
memory):
{
}
END {
}
a[NR] = $0 # index using record number
for (i = NR; i>0; --i)
print a[i]
8. The following program determines the number of lines starting with the same
first field:
{
++a[$1] # array indexed using the first field
}
END { # note output will be in undefined order
for (i in a)
print a[i], "lines start with", i
}
You can use the following program to determine the number of lines in each
input file:
{
}
END {
}
++a[FILENAME]
for (file in a)
if (a[file] == 1)
print file, "has 1 line"
else
print file, "has", a[file], "lines"
9. The following program illustrates how you can use a two-dimensional array in
awk. Assume the first field of each input record contains a product number, the
second field contains a month number, and the third field contains a quantity
(bought, sold, or whatever). The program generates a table of products versus
month.
BEGIN {NUMPROD = 5}
{
array[$1,$2] += $3
}
44 z/OS V1R9.0 UNIX System Services Command Reference