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10. Limits, a few minor ones

The following limits apply.

There must not be any ASCII TAB characters in the data. This is the primary limit as the ASCII TAB character is the delimiter in tables. The following names are reserved to the awk language, and should not be used to indicate column names:

BEGIN, END, break, continue, else, exit, exp, for, getline, if, in, index, int, length, log, next, print, printf, split, sprintf, sqrt, substr, while, and possibly others, depending on the implementation of your awk (i.e. mawk, gawk, etc.). Refer to the man page and the documentation of you awk interpeter.

One way of overcoming (elegantly :-) the few limitations on the special characters that may be contained in a table is to use their ASCII representations, the same way it is done in sgml, html and other text processing systems. So the <TAB> (horizontal tab) character can be represented by the ASCII sequence '&#11;', the <N> (newline) character will be '&#10;', and so on.

The number of columns in a table may be limited to 32.768 by some AWK implementations (I think mawk is one of those). It should not be a problem though, as it is a very high number anyway. In spite of this, mawk is very fast and I recommend it over other AWK implementations.


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