Su and run single line command

Shell Programming and Scripting
1

myenv.sh script sets LOG_DIR variable.
I can run the script and echo the variable in a single line as:

# First set LOG_DIR to some dummy 'NONE' value
[ysrini@linuxapp01a ~]$ export LOG_DIR="NONE"
[ysrini@linuxapp01a ~]$ echo ${LOG_DIR}
NONE

[ysrini@linuxapp01a ~]$ cat /tmp/bin/myenv.sh
export LOG_DIR="/tmp/log"

#The below command doesn't show the value from myenv.sh
[ysrini@linuxapp01a ~]$ /tmp/bin/myenv.sh; echo ${LOG_DIR}
NONE

# using dot and space works
[ysrini@linuxapp01a ~]$ . /tmp/bin/myenv.sh; echo ${LOG_DIR}
/tmp/log

Now I want to run the above command as another user, let's say the other user is 'ysrini' itself

#First set LOG_DIR to some dummy 'NONE' value
[ysrini@linuxapp01a ~]$ export LOG_DIR="NONE"
[ysrini@linuxapp01a ~]$ echo ${LOG_DIR}
NONE

[ysrini@linuxapp01a ~]$ su - ysrini -c ". /tmp/bin/myenv.sh; echo ${LOG_DIR}"
Password: 
NONE

Why is the command ". /tmp/bin/myenv.sh; echo ${LOG_DIR}" output /tmp/log without 'su' and NONE with 'su'?

Thanks,
-srinivas y.

2

This string: ". /tmp/bin/myenv.sh; echo ${LOG_DIR}" substitutes ${LOG_DIR} before su is run. Use single-quotes ' ' instead to prevent it from substituting.

1 Like
3

Thanks Corona, single quotes did the work !