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The coNCePTuaL compiler (ncptl ) honors the following environment variables:
c_udgram
backend unless the -
-backend compiler option designates a
different backend. See Compiling
coNCePTuaL programs, for more information.The following environment variables are honored when running a coNCePTuaL program (any backend):
FOR EACH i IN {1, ..., 10} {IF i IS EVEN THEN TASK 0 LOGS i AS "Even numbers" THEN TASK 0 LOGS i AS "All numbers"}
Buffering data in memory enables that sort of
“two-dimensional” logging. However, it is not robust to
computer crashes or uncatchable signals
(e.g., SIGKILL
). Consequently, every
LOGS
statement (see Writing to a log
file) which is executed at least NCPTL_CHECKPOINT
seconds after the previous one forces the coNCePTuaL run-time library to write its partial data
to the log file. Specifically, the library flushes its partial-data
buffers then rewinds the write pointer to the beginning of that
partial data. Hence, the partial data is overwritten by a later
checkpoint or by the complete data set.
Smaller values of NCPTL_CHECKPOINT
provide more robustness to crashes and uncatchable signals. Larger
values put less stress on the filesystem. As a special case, if
NCPTL_CHECKPOINT
is set to ‘0’
then log-file checkpointing is disabled altogether.
picl
backend (see The
picl backend). See Variables
and data types, for more information.fork()
, system()
, popen()
, and other process-spawning functions. The result is
that some information will be omitted from the log-file prologue.
NCPTL_NOFORK
is intended to be used on systems in which such
functions corrupt messaging-layer state, hang or crash processes,
or wreak other such havoc.