I have a script in which I connect as sysdba and run a query.The script works perfectly fine when I run it standalone by sh command.But when I run the script from a cronjob the script runs but the sql part is omitted .
My script is like
echo "before connection"
sqlplus / as sysdba << EOF
Select * from dual
EOF
It works perfectly fine when I run by:
sh script_name.sh
But When I run by a cronjob the connection part is omitted only line which I get in my logs in "before connection"
What could be the solution of this problem?
Perhaps you get the error sqlplus not found. When run from crontab.
You have to export your PATH variable in the script explicitly. Else, load the .profile itself, if needed. Because, your crontab just executes the script, without defining the variables that you had in your .profile.
Add this to your script, to always load your .profile
. $HOME/.profile
OR
. ~/.profile
If you are running on UNIX (UNIX-like) systems, shebang is mandatory. Have you tried shebang on the first line ? (bash is the shell of choice in my systems)
#!/bin/bash
More explanation here.
Related
I've found a very strange issue, when in linux terminal I type "enable -n trap", it would disable the trap linux builtin command. But if I put it into a script like
#!/bin/bash
enable -n trap
and then run the script, there's no error but the command is also not disabled. Really appreciate if someone could share what is happening and how to run it in some file instead of directly in the terminal. Thank you!
The enable command only affects the current shell. When you run a script, that script is executed in a new process, so:
A new shell starts
The enable command runs and disables the trap command in that shell
The shell exits
If you want to affect the current shell, your only option is to source the script using the . (or source) command. If the script is named disable-trap.sh and is in your $PATH, you can run:
. disable-trap.sh
You can also provide a full path to the script:
. /path/to/disable-trap.sh
Sourcing a script like this is largely equivalent to typing the same commands in at the command line: it executes the instructions in the script in the current shell, rather than spawning a new process.
I've just created a script, let's say, "helloworld.sh".
The script doesn't yet have execution permissons: -rw-rw-r--
If I try to execute that script with: "./helloword.sh", I'll get an error message, as expected. But, if I try to execute that same script as: . helloword, it will execute with no problems.
How? Why does that happen?
This happens because on Linux the "." (dot) alone is a built-in command that execute the script within your current session with your current shell. This is the same as calling the script with source command (the BSD default method). It's almost the same than execute with bash helloworld.sh.
When you call the script with ./helloworld.sh or /root/helloworld.sh the shell will try to figure out how to execute it, if the file is a binary, it will simply run, if it is a script, the shell will read the first line looking for the interpreter. To do this, you'll need execution permission.
To simplify:
One is a command;
The other one is a path.
You can even run:
. --help
About . against bash:
This is why we use . or source to load variables from a file in our session, for example, when we change ~/.bashrc and reload it without login again.
You can see this happens when you execute:
. /etc/os-release
All variables defined inside this file will be loaded and available in your current shell session.
The same will not happen if you execute:
bash /etc/os-release
Because you opened a "new session" inside that bash that you called, the new bash executes and close, cleaning the session.
The same process happen if you give execute permission +x to the script, because when you call the script with ./ or something like that, a new session will be created too.
I'm trying to run some crawler with Linux crontab.
This should go to the Python environment with
pyenv shell jake-crawler
Here is my crontab -e
*/10 * * * * /home/ammt/apps/crawler/scripts/bat_start.sh
This will run every 10 minutes. This command line works fine when I type
(jake-crawler) [jake#KIBA_OM crawler]$ /home/jake/apps/crawler/scripts/bat_start.sh
[DEBUG|run.py:30] 2017-09-24 19:55:49,980 > BATCH_SN:1, COLL_SN:1, 1955 equal 0908 = False
Inside of bat_start.sh I have init.sh which changes the environment to Python.
Here is my init.sh
#!/usr/bin/env bash
export PATH="${HOME}/.pyenv/scripts:$PATH"
eval "$(pyenv init -)"
eval "$(pyenv virtualenv-init -)"
pyenv shell jake-crawler
This has no problem when I personally run it from command line. But when cron run it by itself, it cannot find the pyenv command.
I think that you can specify which user should run that script in cron configuration file.
So, if that script is working with your user, then define it in your cron configuration filr.
See this answer for example... https://stackoverflow.com/a/8475757/3827004.
There are two things that diferentiate when you launch an application from the terminal, and when you do from a crontab file:
the environment is not the same, at least if you don't execute your .profile script from your cron job.
You don't have access to a terminal. Cron jobs don't use a terminal, so you will not be able, for example to open /dev/tty. You will have to be very careful on how redirections are handled, as you have them all directed to your tty when running on an interactive session, but all of them will be redirected possibly to a pipe, when run from cron(8).
This makes your environment quite different and is normally a source of errors. Read crontab(1) man page for details.
I have a bash script .sh which needs to be executed as a Target Simulator in Eclipse. The problem is, if I run the script with sh run.sh command in terminal, it throws Bad Substitution error. But it works perfectly with bash run.sh. Apparently, Eclipse run it with sh command cause it gives the same error in console. But how can I make Eclipse to run the script with bash instead?
I'm on Ubuntu 13.10.
bash and sh aren't the same shell. There are many constructs valid in bash that are not understood by sh.
Have you provided a correct sheebang as the first line of your script?
#!/bin/bash
If so -- and if Eclipse insist on running script with sh, you still have the option of wrap your script in a heredoc and pass it to bash explicitly:
sh$ cat run.sh
bash << EOF
#
# Here is your bash script
#
EOF
This is mostly a hack until you find how to instruct Eclipse of using the right shell. I'm sure there is a way!
I am running a shell script by which we are scheduling a task using at command. But it schedules the at task but its not running the same beacuse its using shell /sbin/nologin when we are calling it from php code. It works fine if we run it from terminal.
You should check the "$PATH" env variable. When you are logged in from terminal the shell has initialized it's search path via .bashrc etc. "cron" or "at" jobs don't do that.
So try to log the environment variables to a file in your 'at' jobs and check if it is set up right.