Programming tips and known problems

Known problems with built-in utilities

The following are known problems with built-in utilities.


The regex built-in utility used in a text descriptor, with a template argument that cat's a file containing tabs and newlines, does not preserve the tabs and newlines in the opened text frame.


The longline utility cannot be used to determine the longest line of a header read with the readfile utility if the text descriptor also contains a readfile.

If a menu contains a readfile in a backquoted expression on a line by itself and the file read contains a series of backquoted expressions on lines by themselves, the first one of those lines is ignored. Making the first line a blank or a comment will get around this.

Co-processing utilities

The frame border of a form may not complete until input is provided from the keyboard when co-processing is used.

Input and output strings from co-processing should not use non-alphabetic printable characters, because the FMLI special characters are not correctly transmitted.

When the reread descriptor is used with co-processing and the vsig utility causes the reread to occur frequently, the FMLI process may grow out of memory space.


Omitting the terminating fi causes the remainder of a frame definition file to be incorrectly parsed.

The standard output of if-then-else cannot be redirected using the > operator. However, individual parts of the statement (the then part and the else part) can be.

A null statement following a then followed by an else can cause a syntax error.


The fmlcut built-in utility reads standard input piped to it, but does not read a file redirected using <.

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UnixWare 7 Release 7.1.4 - 27 April 2004