Linux – Shell script not running as by “./” but it runs by “sh”

bashbash-scriptingfile-permissionslinuxshell

I am running a script on arm target board as a super user, i.e., as a root user. But the script is not executing if i run it with following syntax

root@freescale$ ./Script.sh 
-sh: ./Script.sh: Permission denied

I already gave the read and execute permissions(+rx) by using chmod command. On executing "ls -l" command I get following attributes

root@freescale$ ls -l | grep Script.sh
-rw-rw-rw-    1 root     root          362 Jul  2 08:47 Script.sh

"x" is not there in the file attributes column, whereas the chmod command executed successfully.
On the other hand, this script runs when I run it as

root@freescale$ sh Script.sh

Can anyone help me to answer this situation?

Best Answer

even if your "chmod" returns success, the execute bit does not really get turned on, as "ls" shows, therefore I conclude something is transparently preventing you from changing the file mode on the filesystem.

what does "lsattr Script.sh" shows?

can you put the script into a ramdrive or another filesystem on the same host and try again?

Related Solutions

Ubuntu – How To Give Execute Permissions To Root User File In Ubuntu

The author made a number of mistakes.

The script should be created, chmod'd and executed as root.
The script is missing the shebang to tell it what interpreter to use.

This is what you should be doing:

As root (sudo -s) create the file /root/fw.stop:

$ sudo -s
Enter foo's password:
# nano -w /root/fw.stop

Then enter the following script (note the change in the first line):

#!/bin/sh
echo "Stopping firewall and allowing everyone..."
iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
iptables -P INPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -P OUTPUT ACCEPT

Then you can chmod it (still as root):

# chmod +x /root/fw.stop

Then you can run it (yes, still as root):

# /root/fw.stop

If you want to run it as anyone other than root then you should use sudo (sudo /root/fw.stop). The setuid bit is possible but a serious security hole as it would allow anyone to run the script.

Linux – how to grant execute permission without read permission

The problem with scripts is that the script is not what is running, but the interpreter (bash in this case).

The interpreter needs to read the script.

Since reading the file is forbidden then it can't be executed inside the interpreter.

This is different from a program, because programs are loaded directly into the kernel.

One solution is to use a compiler that will generate a C program equivalent to the script, like SHC, that you can download from here or from this guide.

Best Answer

Related Solutions

Ubuntu – How To Give Execute Permissions To Root User File In Ubuntu

Linux – how to grant execute permission without read permission

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