sylvaticus wrote:
> Hello,
> is it possible to append some data on a text output file appending
> the data to each row, and without use too much computational I/O ??

There is no such thing as "each row" when files are concerned. Each
file is a stream of characters. Only your interpretation of some
specific character (like the "newline" \n for example) makes the file
*appear* to contain "rows" (we usually call them "lines").

>
> Instead of the classical way:
>
> VARX VARY VARZ...
> year1 x1 y1 z1
> year2 x2 y2 z2
>
> .. I would like to use the much more redeable:
>
> year1 year2 ..
> VARX x1 x2 ...
> VARY y1 y2 ...
> VARZ z1 z2 ...
> ...
>
> where the 1,2 series are wrote at different times.. a sort of a
> appendByRow() function.. and I would avoid of loading the whole file
> in memory and then printing it line-by-line, as I have to do it on
> approx 40,000 (few KB) files.. and I am worry that the second approach
> would take years :-)))
>
> is it possible to do it in a efficient way (e.g. seeking to the right
> place, delete the newline and appending there) ??

No. The usual approach is writing a new file where "each line" is
replicated and "expanded" to contain new information.

V
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