Hi,
I am thinking about writing a log daemon for a multi-processed ksh application (yes - I know that high-level language would be a better option).
My question is as follows:
If many processes (many scripts) will try writing to a single log file:
print "message" > common.log
Will it work or is there a risk of collision between them?
If there is such a risk then is it better to use named pipes or doors for such logging system?
And maybe there is some alternative?
Well, it depends what you do you understand as collision, if the log file will be used for simple messages, then "echo `date` "log this message" >> file.log would be sufficient. Otherwise, for more sophisticated tasks, consider mkfifo, which I see, you are already familiar with.
Maybe I will give you some more details.
I was to take code created by someone else. For logging from several simultaneous processes they are using many log files and from time to time they merge them all into one.
Until now I was thinking that when you are doing:
print "some even quite long message" >> file.txt
from several processes at once, then it would not interfere.
But they told me that they were receiving logs like:
"log number one
log numbelog number threer two
log number four"
Im ,y understanding this should never occur. But if this is the case then FIFO pseudo-device would be the best choice.
Anyway - I asked because according to my knowledge situation described by the other guy should not occur unless he is doing something like:
print "log number " >>file.txt
print "one" >>file.txt