# #lineson, #linesoff¶

## Purpose¶

The #lineson command causes GAUSS to embed line number and file name records in a program for the purpose of reporting the location where an error occurs. The #linesoff command causes GAUSS to stop embedding line and file records in a program.

## Format¶

#lineson
#linesoff

## Remarks¶

In the “lines on” mode, GAUSS keeps track of line numbers and file names and reports the location of an error when an execution time error occurs. In the “lines off” mode, GAUSS does not keep track of lines and files at execution time. During the compile phase, line numbers and file names will always be given when errors occur in a program stored in a disk file.

It is easier to debug a program when the locations of errors are reported, but this slows down execution. In programs with several scalar operations, the time spent tracking line numbers and file names is most significant.

These commands have no effect on interactive programs (that is, those typed in the window and run from the command line), since there are no line numbers in such programs.

Line number tracking can be turned on and off through the user interface, but the #lineson and #linesoff commands will override that.

The line numbers and file names given at run-time will reflect the last record encountered in the code. If you have a mixture of procedures that were compiled without line and file records and procedures that were compiled with line and file records, use the trace command to locate exactly where the error occurs.

The currently active call error message will always be correct. If it states that it was executing procedure xyz at line number nnn in file ABC and xyz has no line nnn or is not in file ABC, you know that it just did not encounter any line or file records in xyz before it crashed.

When using #include’d files, the line number and file name will be correct for the file the error was in within the limits stated above.

See also

Functions trace()