Full Discussion: Rounding issue with awk
Rounding issue with awk Post 302339057 by vidyadhar85 on Wednesday 29th of July 2009 03:40:55 PM
07-29-2009
try this..

## Rounding off using BC.

Hello again. I'm trying to use BC to calculate some numbers in a shell script. I want to have the numbers rounded off to 1 decimal place. for example: initsize=1566720 zipsize=4733 I'm trying to get the ratio between them. the equation is: ((\$initsize-\$zipsize)/\$initsize)*100 so...

## Rounding off to the next whole number

Hello, I searched a lot on this Forum. Please help me with the below problem. I want to divide two numbers and the result should be the next nearest whole number. E.G. Dividing 10.8/5 ideally gives 2.16. But the result should be 3 i.e. rounded off to the next whole number. Any help will...

## Annoying rounding issue in awk

Hello I am getting this very annoying issue in awk: awk '{a=12825;b=a*1.25; print b}' test 16031.2 Thing is the multiplication result is wrong... Result should be 16031.25. I think the issue only happens on bigger numbers. What can I do to get passed this? Thanks by advance

## Rounding Script Help

I need some help with my rouding script. I have started pretty much from scratch and have no idea if its correct or even close but I have been trying and have gotten to this point. i keep getting syntax errors and im not sure what is wrong. Here is what I got let value=\$1; while do let...

## AWK rounding up numbers

Hi, I have managed to round up numbers by using the following command: echo "5.54" | awk '{printf "%.0f\n", \$1}' result 6 How can I round up all the numbers in a column in a file and print the lines with the new calculated totals? Thanks,

## awk, floating point and rounding

I had a person bring an interesting problem to me that appears to involve some sort of rounding inside awk. I've verified this with awk and nawk on Solaris as well as with gawk 3.1.5 on a Linux box. The original code fragment he brought me was thus: for (index=0; index < 1; index=index+.1) ...

## awk calculation automatically rounding off the output

I have some calculation in my script which is similar to the below example . I find that sometimes when using large decimal digits, the output gets automatically rounded off and it is affecting the program. I am not able to understand what is happening here.. awk '{ a=6.32498922 a1=6.324...

## printf (awk,perl,shell) float rounding issue

Hi guys, could someone throw some light on the following behaviour of printf (I'll start with info about the system and the tool/shell/interpreter versions)?: \$ uname -a Linux linux-86if.site 3.1.0-1.2-desktop #1 SMP PREEMPT Thu Nov 3 14:45:45 UTC 2011 (187dde0) x86_64 x86_64 x86_64...

## Variable value substitution issue with awk command issue

Hi All, I am using the below script which has awk command, but it is not returing the expected result. can some pls help me to correct the command. The below script sample.ksh should give the result if the value of last 4 digits in the variable NM matches with the variable value DAT. The...

## [awk] rounding a float number?

Heyas Trying to calculate the total size of a file by reading its bitrate. Code snippet: fs_expected() { # # Returns the expected filesize in bytes # pr_str() { ff=\$(cat \$TMP.info) d="\${ff#*bitrate: }" echo "\${d%%,*}" | \$AWK '{print \$1}' | head -n 1 } t_BYTERATE=\$((...
```A2P(1)							 Perl Programmers Reference Guide						    A2P(1)

NAME
a2p - Awk to Perl translator

SYNOPSIS
a2p [options] [filename]

DESCRIPTION
A2p takes an awk script specified on the command line (or from standard input) and produces a comparable perl script on the standard out-
put.

OPTIONS

Options include:

-D<number>
sets debugging flags.

-F<character>
tells a2p that this awk script is always invoked with this -F switch.

-n<fieldlist>
specifies the names of the input fields if input does not have to be split into an array.  If you were translating an awk script that
processes the password file, you might say:

Any delimiter can be used to separate the field names.

-<number>
causes a2p to assume that input will always have that many fields.

-o   tells a2p to use old awk behavior.	The only current differences are:

*	 Old awk always has a line loop, even if there are no line actions, whereas new awk does not.

*	 In old awk, sprintf is extremely greedy about its arguments.  For example, given the statement

print sprintf(some_args), extra_args;

old awk considers extra_args to be arguments to "sprintf"; new awk considers them arguments to "print".

"Considerations"

A2p cannot do as good a job translating as a human would, but it usually does pretty well.  There are some areas where you may want to
examine the perl script produced and tweak it some.  Here are some of them, in no particular order.

There is an awk idiom of putting int() around a string expression to force numeric interpretation, even though the argument is always inte-
ger anyway.  This is generally unneeded in perl, but a2p can't tell if the argument is always going to be integer, so it leaves it in.  You
may wish to remove it.

Perl differentiates numeric comparison from string comparison.  Awk has one operator for both that decides at run time which comparison to
do.  A2p does not try to do a complete job of awk emulation at this point.  Instead it guesses which one you want.  It's almost always
right, but it can be spoofed.  All such guesses are marked with the comment ""#???"".  You should go through and check them.  You might
want to run at least once with the -w switch to perl, which will warn you if you use == where you should have used eq.

Perl does not attempt to emulate the behavior of awk in which nonexistent array elements spring into existence simply by being referenced.
If somehow you are relying on this mechanism to create null entries for a subsequent for...in, they won't be there in perl.

If a2p makes a split line that assigns to a list of variables that looks like (Fld1, Fld2, Fld3...) you may want to rerun a2p using the -n
option mentioned above.	This will let you name the fields throughout the script.  If it splits to an array instead, the script is probably
referring to the number of fields somewhere.

The exit statement in awk doesn't necessarily exit; it goes to the END block if there is one.  Awk scripts that do contortions within the
END block to bypass the block under such circumstances can be simplified by removing the conditional in the END block and just exiting
directly from the perl script.

Perl has two kinds of array, numerically-indexed and associative.  Perl associative arrays are called "hashes".	Awk arrays are usually
translated to hashes, but if you happen to know that the index is always going to be numeric you could change the {...} to [...].  Itera-
tion over a hash is done using the keys() function, but iteration over an array is NOT.	You might need to modify any loop that iterates
over such an array.

Awk starts by assuming OFMT has the value %.6g.	Perl starts by assuming its equivalent, \$#, to have the value %.20g.  You'll want to set
\$# explicitly if you use the default value of OFMT.

Near the top of the line loop will be the split operation that is implicit in the awk script.  There are times when you can move this down
past some conditionals that test the entire record so that the split is not done as often.

For aesthetic reasons you may wish to change the array base \$[ from 1 back to perl's default of 0, but remember to change all array sub-
scripts AND all substr() and index() operations to match.

Cute comments that say "# Here is a workaround because awk is dumb" are passed through unmodified.

Awk scripts are often embedded in a shell script that pipes stuff into and out of awk.  Often the shell script wrapper can be incorporated
into the perl script, since perl can start up pipes into and out of itself, and can do other things that awk can't do by itself.

Scripts that refer to the special variables RSTART and RLENGTH can often be simplified by referring to the variables \$`, \$& and \$', as long
as they are within the scope of the pattern match that sets them.

The produced perl script may have subroutines defined to deal with awk's semantics regarding getline and print.	Since a2p usually picks
correctness over efficiency.  it is almost always possible to rewrite such code to be more efficient by discarding the semantic sugar.

For efficiency, you may wish to remove the keyword from any return statement that is the last statement executed in a subroutine.  A2p
catches the most common case, but doesn't analyze embedded blocks for subtler cases.

ARGV[0] translates to \$ARGV0, but ARGV[n] translates to \$ARGV[\$n].  A loop that tries to iterate over ARGV[0] won't find it.

ENVIRONMENT
A2p uses no environment variables.

AUTHOR
Larry Wall <larry@wall.org>

FILES
perl   The perl compiler/interpreter

s2p    sed to perl translator

DIAGNOSTICS
BUGS
It would be possible to emulate awk's behavior in selecting string versus numeric operations at run time by inspection of the operands, but
it would be gross and inefficient.  Besides, a2p almost always guesses right.

Storage for the awk syntax tree is currently static, and can run out.

perl v5.8.9							    2005-03-10								    A2P(1)```

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