Question

I’m calling a c program using crontab.

If I call the program directly, everything is fine.
If the program is called by cron, my .log files can’t be opened.

the program is in a directory

/stuff1/stuff2/stuff3/program

all pathnames in the program are absolute
just to make sure, I chmod 777’d everything in stuff3

EDIT:
The line from crontab is

0 * * * * /stuff1/stuff2/stuff3/program

EDIT2:

Issue isn’t with cron, if I run it like this

cd /
/stuff1/stuff2/stuff3/program

it fails

if I run it like this:

cd /stuff1/stuff2/stuff3/program
program

everything is peachy.
What does linux change that could affect my program when run in those two different ways?

Answer 1

The problem was that the program I was forking was attempting to write to ./
This caused permission failures as cron doesn’t run the program from the directory it is in, rather it runs it from some other directory that I didn’t have write permissions in.