Tag: eval
How to run a background command in script as a parameter in unix shell scripts
by Frederick Tybalt on Jun.21, 2013, under Programming, Unix
Many times you would have tried running a command or script directly in a unix script by providing the name and path of the script. Also you would have run scripts are commands by assingning to variables. But by any chance if you had tried running a script or command assingned to variables you might got struck and which also gives you a vauge error message.
For example consider a script param.sh as below
echo $1 $1
And you are running the scipt as
./param.sh 'ls -ltr &'
You would be getting a error message
./& not found
This issue can be resloved by using eval command in param.sh and the new script looks as below.
eval $1
eval command will take an argument and construct a command of it, which will be executed by the shell. It is an inbuit command and there is the man page http://www.unix.com/man-page/posix/1posix/eval/