How to run rman with cron under RHEL3?

Question

I am exhausted with all my options and knowledge with this. Tried 2 days with all possibilities, but failed. I have a Oracle 10g r2 (10.2.0.2) on a RHEL3 box. I wrote an orabackup.sh file as
rman target sys/pw@backup nocatalog <<EOF
run
{ backup as backupset incremental level 1 cumulative device type disk tag 'Thu_full_bkup%LEVEL_1'  database;
recover copy of database;
backup device type disk tag 'Thu_full_bkup%LEVEL_1' archivelog all not backed up;
delete noprompt obsolete device type disk;
exit
EOF
I have tried this with cron (crontab) under both oracle and root env with $PATH containing the $ORACLE_HOME/bin as the first. The cron job under the crontab is as
44 17 * * * "/home/oracle/orabackup.sh >> /home/oracle/rmanbk.log 2>&1". And it kept returning with either "RMAN: command not found" or the "/bin/sh: line 1: /home/oracle/orabackup.sh >> /home/oracle/rmanbk.log 2>&1: No such file or directory". I had included su - oracle -c in the either script or cron job with or without quote, but result the same error. Does not matter the cron phrase was /home/oracle or without it. Some sites suggested to enter the #!/bin/sh as the first line of the script, tried that and failed too. So what exact I should phrase both the script and cron to let it run automatically. I could run the script manually under either oracle and root env.

Answer 1

I'll try to rephrase. There are (at least) three cases:
1. When you login with a terminal (e.g. with telnet, ssh) then the file ".bash_profile" is run automatically if your default shell is bash (check $SHELL to verify). In this case your personally-configured $PATH will be known with no effort on your side.
2. When a script is run by cron through crontab, then no login script is run automatically. In that case, you need to explicitly tell the script to run your login script, i.e. ".bash_profile". Otherwise, $PATH will not include $ORACLE_HOME/bin.
3. This case was not discussed before in this thread: When cron runs a job following "at" or "batch" commands, then the job will know all exported variables that were defined in the executing session. This shows that running a script with "at" is not a sufficient test before letting it run through crontab.
I may have not been perfectly correct here. It's best if you read the manuals for "bash", "at", and "cron" to know all about the subject.