Re^3: Format, empty vars, and fixed-width records

As I showed with the decimal field at the beginning of the records above, you can truncate integer fields by using %N.Ns. Unfortunately, the truncation always occurs on the right regardless of whether you use '-' or not:

[0] Perl> printf "%2.2s\n", $_ for 9, 99 .. 101;;
 9
99
10
10
[0] Perl> printf "%-2.2s\n", $_ for 9, 99 .. 101;;
9
99
10
10
[download]

Which may not be what you want. The real problem (sic) is floating point numbers, there's just no sensible way to squeeze them into a fixed width field if they stray beyond a limited range:

printf "%-8.8s\n", sprintf '%8f', $_ 
    for map{ 1.23456789 * $_} map{ "1e$_" } -10 .. 10;;
0.000000
0.000000
0.000000
0.000000
0.000001
0.000012
0.000123
0.001235
0.012346
0.123457
1.234568
12.34567
123.4567
1234.567
12345.67
123456.7
1234567.
12345678
12345678
12345678
12345678
[download]

And its worse if you want or need to maintain point alignment.

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Re^4: Format, empty vars, and fixed-width records by ikegami (Patriarch) on Apr 22, 2008 at 02:56 UTC
You could handle number overflow like Excel does: `sub format_num { my $s = sprintf('%5.2f', $_[0]); return length($s) > 5 ? 'XXXXX' : $s; }` [download]	[reply] [d/l]
Re^5: Format, empty vars, and fixed-width records by BrowserUk (Patriarch) on Apr 22, 2008 at 03:32 UTC
I guess that depends upon what the receiving program is expecting under those circumstances. Maybe something like '#Inf ' or '#-Inf' makes sense? Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. "Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."	[reply]


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