Hello,

I wrote a simple script to see if firefox is running...
However, the ps command is not executed, when I open the logfile I see: "DEBUG LINE 4" and not DEBUG LINE 5, so "ps -e" is never executed despite using the full path of the ps command.

Here is my script:

#!/bin/bash -l
# simple script to test if firefox is running...

PS=/usr/bin/ps echo "DEBUG $LINENO"
$PS -e | fgrep firefox echo "DEBUG LINE $LINENO"

What am I doing wrong?

Thanks!!

It's "/bin/ps", not "/usr/bin/ps".

I changed it to "/bin/ps" but still not working...
I get the following error message:

StartFirefox.sh: line 5: -e: command not found

so the variable $PS is not recognized...

But my script used to be like that:

#!/bin/bash
#Script to start firefox

ps -e | fgrep firefox
if [ $? -eq 1 ]; then
#command to start firefox

It ran fine when executing manually, but with crontab, it does not work. So I thought someting could be wrong with the ps command, but no...

You can't print/echo in a cron job unless the output is redirected to /dev/null or a file. There is no
console attached to the program.

This is my full script, it runs fine when I execute it manually, but NOT with crontab... how come? :O

PS=/bin/ps
$PS -e | grep "process name"
if [ $? -eq 1 ]; then
LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/laurent/ screen -d -m ./"start binary"& echo "LINE $LINENO"
echo "`date +"%A %d %B %Y, %H:%M:%S"` --> process started."
else
echo "`date +"%A %d %B %Y, %H:%M:%S"` --> process is already running."
fi

Doing this in cron makes no sense. For one thing you are writing to STDOUT which you don't have access to. For another cron runs programs as root unless your system has PAM configured to allow regular users to enter cron jobs.

I'm not certain if you can reattach a screen session if there is not a terminal to attach the screen session to in the first place. You probably have no terminal open with read/write access for screen to be attached to. In the very least, doing so might need to be done before the ps command, or use a variable for the output of the ps command, and redirect stderr to /dev/null. You may need to use ps to indentify processes running in terminals.
E.G.: ttys=$(ps -o tty -u jschiwal | sed '1d;/^\?/d')
Reason being that if you don't have any terminals open, you don't have permission to read or write to the device.

Lastly, why do you want to launch firefox in the background. Why can't you use your eyes to see if firefox is running. It is an interactive program, not a service that runs in the background.

Well okay, to keep it simple, I removed all that "ps" and "screen" crap, and this is my very simple script now:
To start a (LEGAL) game server at reboot:
When this works, I will attach it to screen afterwards...

#/bin/bash
#StartServer.sh
/home/laurent/Games/Cod4/co4_lnxded +exec server.cfg +map_rotate&

It runs perfectly fine when executing manually, but not with cron.
This is my crobtab using: 'sudo crontab -e':

@reboot cd "/home/laurent/Games/Cod4"; ./StartServer.sh

When I reboot my server and ps the process, it doesn't exists...
How come?

i am facing same issue where manual executing the script giving the result but when we configure the same script on crontab and giving 2>&1 >> output.log its not working.

Any resolution on this.
******************************
#!/bin/sh -c

###edit the following
service=Runner
email=XXXXXXXXXXXXXXXXXXXXXX
PROCESSID=`ps -elf | grep -v grep | grep Runner | awk '{print $4}'`
###stop editing

host=`hostname -f`

D=`date +%c`
if (( $(ps -ef | grep -v grep | grep $service | wc -l) > 0 )); then
echo "$service is running @ $D"
echo "Utlzation of $service"
ps -p $PROCESSID -o %cpu,%mem
fi

Same solution: Use absolute path names for commands. cron doesn't have an environment, so it doesn't know where ps, grep, hostname, etc. are.
Use from the terminal to identify the absolute path for each command.

And, generally speaking, you should start your own thread instead of reopening a 7-year-old thread.

You can also set PATH env variable at top of script

At the top of your script have
No options!
For example -l would run your .profile first, that is not meant to be run from cron.