STRAIN(1M)                                                          STRAIN(1M)



NAME
     strain - extract errors from build log files.

SYNOPSIS
     strain [ -h | -s ] [ -w ] [ -c context ] <logfile>

DESCRIPTION
     strain is used to extract error messages from a build log. It displays
     the error and a certain amount of context around it.  strain can work on
     an arbitrary input, but works best with input that has special markers
     known to strain.  For large build logs, strain is an effective tool in
     determining build success or failure.

     strain works by folding the log file into 512 character lines and feeding
     these lines through a nawk(1) script which looks for known error messages
     patterns.  When strain encounters an error, it simply saves that line
     number and continues scanning.  If strain hits either a marker or
     accumulates context lines, it dumps the line in errors and the
     surrounding context.  Markers are lines beginning with:  @<,@>,===,

OPTIONS
     -c    accumulate context lines before dumping any errors.  Default is 15.

     -h    show highlights only. This option prints out every line that begins
           with :-( (Mk's "subsystem build failure" identifier) or = (the
           "subsystem build begin" identifier printed by Mk and some
           makefiles).

     -s    provide a summary list of directories with errors before the strain
           output.

     -w    show warning messages, in addition to error messages.

WARNINGS
     The -h and -s options are mutually exclusive.

SEE ALSO
     nawk(1), fold(1), makewrapper(1)

BUGS
     strain's algorithm for finding bugs is simply a list of patterns to
     search for.  New tools often report errors in a way that strain doesn't
     understand.












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