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

Examples
Output
The print statement prints its arguments with only simple formatting. If it has no
arguments, it prints the entire current input record. awk adds the output record
separator ORS to the end of the output that each print statement produces; when
commas separate arguments in the print statement, the output field separator OFS
separates the corresponding output values. ORS and OFS are built-in variables,
whose values you can change by assigning them strings. The default output record
separator is a newline, and the default output field separator is a space.
The variable OFMT gives the format of floating-point numbers output by print. By
default, the value is %.6g; you can change this by assigning OFMT a different string
value. OFMT applies only to floating-point numbers (ones with fractional parts).
The printf statement formats its arguments using the fmt argument. Formatting is
the same as for the built-in function sprintf. Unlike print, printf does not add output
separators automatically. This gives the program more precise control of the output.
The print and printf statements write to stdout. You can redirect output to a file or
pipe.
If you add >expr to a print or printf statement, awk treats the string value of expr
as a filename, and writes output to that file. Similarly, if you add >>expr, awk sends
output to the current contents of the file. The distinction between > and >> is
important only for the first print to the file expr. Subsequent outputs to an already
open file append to what is there already.
You cannot use such ambiguous statements as:
print a > b c
Use parentheses to resolve the ambiguity.
If you add |expr to a print or printf statement, awk treats the string value of expr
as an executable command and runs it with the output from the statement piped as
input into the command.
As mentioned earlier, you can have only a limited number of files and pipes open at
any time. To avoid going over the limit, use the close function to close files and
pipes when you no longer need them.
print and printf are also available as functions with the same calling sequence, but
no redirection.
1. The following example:
awk ’{print NR ":" $0}’ input1
outputs the contents of the file input1 with line numbers prepended to each
line.
2. The following is an example using var=value on the command line:
awk ’{print NR SEP $0}’ SEP=":" input1
awk can also read the program script from a file as in the command line:
awk –f addline.awk input1
which produces the same output when the file addline.awk contains:
awk
Chapter 2. Shell command descriptions 43