oawk(1) DG/UX 5.4.2 oawk(1)
NAME
oawk - old pattern scanning and processing language
SYNOPSIS
awk [ -Fc ] [ prog ] [ parameters ] [ files ]
DESCRIPTION
Although you can still use the oawk utility, it has been superseded
by the newer awk utility. See awk(1). Oawk scans each input file
for lines that match any of a set of patterns specified in prog.
Each pattern in prog can have an associated action that will be
performed when a line of a file matches the pattern. The set of
patterns may appear literally as prog, or in a file specified as -f
file. The prog string should be enclosed in single quotes (') to
protect it from the shell. The -Fc option specifies c as a field
separator.
Parameters, in the form x=... y=... etc., may be passed to oawk. The
parameters cannot be array elements.
Files are read in order; if there are no files, the standard input is
read. The file name - means the standard input. Each line is
matched against the pattern portion of every pattern-action
statement; the associated action is performed for each matched
pattern.
An input line is made up of fields separated by white space. (This
default can be changed by using the -Fc option or FS; see below).
The fields are denoted $1, $2, ...; $0 refers to the entire line.
A pattern-action statement has the form:
pattern { action }
A missing action means print the line; a missing pattern always
matches. An action is a sequence of statements. A statement can be
one of the following:
if ( conditional ) statement [ else statement ]
while ( conditional ) statement
for ( expression ; conditional ; expression ) statement
break
continue
{ [ statement ] ... }
variable = expression
print [ expression-list ] [ >expression ]
printf format [ , expression-list ] [ >expression ]
next # skip remaining patterns on this input line
exit # skip the rest of the input
Statements are terminated by semicolons, new-lines, or right braces.
An empty expression-list stands for the whole line. Expressions take
on string or numeric values as appropriate, and are built using the
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oawk(1) DG/UX 5.4.2 oawk(1)
operators +, -, *, /, %, and concatenation (indicated by a blank).
The C operators ++, --, +=, -=, *=, /=, and %= are also available in
expressions. Variables may be scalars, array elements (denoted
x[i]), or fields. Variables are initialized to the null string.
Array subscripts may be any string, not necessarily numeric; this
allows for a form of associative memory. String constants are
enquoted (").
The print statement prints its arguments on the standard output (or
on a file if >expr is present), separated by the current output field
separator, and terminated by the output record separator. The printf
statement formats its expression list according to the format (see
printf(3S)).
The built-in function length returns the length of its argument taken
as a string, or of the whole line if no argument. There are also
built-in functions exp , log , sqrt , and int. The last truncates
its argument to an integer. substr (s, m, n) returns the n-character
substring of s that begins at position m. The function
sprintf(fmt,expr, expr, ... ) formats the expressions according to
the printf(3S) format given by fmt and returns the resulting string.
Patterns are arbitrary Boolean combinations ( !, ||, &&, and
parentheses) of regular expressions and relational expressions.
Regular expressions must be surrounded by slashes and are as in egrep
(see grep(1)). Isolated regular expressions in a pattern apply to
the entire line. Regular expressions may also occur in relational
expressions. A pattern may consist of two patterns separated by a
comma; in this case, the action is performed for all lines between an
occurrence of the first pattern and the next occurrence of the
second.
A relational expression is one of the following:
expression matchop regular-expression
expression relop expression
A relop is any of the six relational operators in C, and a matchop is
either ~ (for contains) or !~ (for does not contain). A conditional
is an arithmetic expression, a relational expression, or a Boolean
combination of these.
You can use the special patterns BEGIN and END to capture control
before the first input line is read and after the last. BEGIN must
be the first pattern, END the last.
A single character c may be used to separate the fields by starting
the program with:
BEGIN { FS = c }
or by using the -Fc option.
Other variable names with special meanings include NF, the number of
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oawk(1) DG/UX 5.4.2 oawk(1)
fields in the current record; NR, the ordinal number of the current
record; FILENAME, the name of the current input file; OFS, the output
field separator (default blank); ORS, the output record separator
(default new-line); and OFMT, the output format for numbers (default
%.6g).
EXAMPLES
$ oawk "length > 72" infile
This form of the command will print only those lines in the file
"infile" that are longer than 72 characters.
$ oawk '{ s += $3 }
> END { print "sum is", s, " average is", s/NR }' salesreport
This form of the command will add up the third column of the file,
"sales_report", and print the sum and average of that sum.
$ oawk '{ for (i = NF; i > 0; --i) print $i }' infile
This form of the command will print each of the fields in reverse
order.
$ cat cmdfile
/page/ { $2 = n++; }
{ print }
$ oawk -f cmdfile n=1 report > numreport
Using the commands in the file "cmd_file", this form of the command
will print file "report", filling in page numbers and outputting file
"num_report" which will be the original report with page numbers.
SEE ALSO
awk(1), nawk(1), grep(1), lex(1), sed(1), printf(3S).
BUGS
Input white space is not preserved on output if fields are involved.
There are no explicit conversions between numbers and strings. To
force an expression to be treated as a number add 0 to it; to force
it to be treated as a string, concatenate the null string ("") to it.
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