export is not working on command prompt

Hi_This_is_Dev · 08-26-2010, 06:49 PM

Hi,

The command export is working inside a shell script, but when I type it at the command prompt / terminal it doesn't work. "export: The command not found" error is displayed instead.

I tried this:

cat test.sh

Code:

abc=123
export abc
echo "Exit status of export abc: $?"

Code:

# bash test.sh
Exit status of export abc: 0

But when I type it at the command prompt:

Code:

# export abc=123

I get the "the command not found" error.

Code:

man export

is also working fine.

I tried it before on my RHEL system and it was working. I have checked

Code:

echo $PATH

which is okay. What could be the problem?

carltm · 08-26-2010, 09:24 PM

It could be that your shell is not of the Bourne Shell family.

What is the output of this command?

grep ^`echo $USER`: /etc/passwd

Hi_This_is_Dev · 08-27-2010, 06:11 AM

Quote:

Originally Posted by carltm

It could be that your shell is not of the Bourne Shell family.

What is the output of this command?

grep ^`echo $USER`: /etc/passwd

I will check that command. But the shell I am using is certainly bash as I have checked the file /etc/passwd several times.

In fact, I have run export on the command prompt before. But I am not sure what is wrong going on this time.

catkin · 08-27-2010, 06:19 AM

What is the output of type export ?

Hi_This_is_Dev · 08-27-2010, 07:20 AM

Quote:

Originally Posted by catkin

What is the output of type export ?

I will post it after 9 hours.

I am at office right now. The problem I observed is on my personal computer at my room.

But thanks for the useful command: type

I have checked this command on the system I am using righ tnow:

Code:

-bash-2.05b# type export
export is a shell builtin
-bash-2.05b# type ls
ls is aliased to `ls --color=tty'
-bash-2.05b# type dir
dir is hashed (/usr/bin/dir)
-bash-2.05b# type echo
echo is a shell builtin
-bash-2.05b# type :
: is a shell builtin
-bash-2.05b#

What does this output, as given above and below, mean?

Code:

-bash-2.05b# type dir
dir is hashed (/usr/bin/dir)

Specifically the term "hashed" used here...?

Hi_This_is_Dev · 08-28-2010, 12:49 PM

Quote:

Originally Posted by carltm

It could be that your shell is not of the Bourne Shell family.

What is the output of this command?

grep ^`echo $USER`: /etc/passwd

I have just found that my shell got changed to csh and it was creating the problem.

Code:

[root@localhost ~]# grep ^"$USER" /etc/passwd
root:x:0:0:root:/root:/bin/csh

I changed it to bash and the problem was resolved!

Code:

[root@localhost ~]# type export
export is a shell builtin

I experimented with these commands:

Code:

[root@localhost ~]# csh
[root@localhost ~]# type export
type: Command not found.
[root@localhost ~]# bash
[root@localhost ~]# type export
export is a shell builtin
[root@localhost ~]# grep ^"$USER" /etc/passwd
root:x:0:0:root:/root:/bin/bash

That is interesting. But I don't remember changing the shell. I had added two users before and just now I added one more:

Code:

[root@localhost ~]# tail -n 3 /etc/passwd
DEV:x:500:500:Dev's Account for Testing Purpose:/home/DEV:/bin/bash
Demo:x:501:502::/home/Demo:/bin/bash
test:x:502:503::/home/test:/bin/bash

and they all have bash as the default shell for their log-in sessions.

Anyways, the problem has taught me some troubleshooting techniques

Quote:

type <command> <enter>

and first where to check when a command is not working, i.e. the log-in shell.

Code:

grep ^"$USER" /etc/passwd

or

Code:

echo $SHELL

Thanks to all of you!

catkin · 08-28-2010, 07:28 PM

Quote:

Originally Posted by Hi_This_is_Dev

What does this output, as given above and below, mean?

Code:

-bash-2.05b# type dir
dir is hashed (/usr/bin/dir)

When a command is not a bash alias, builtin or function, bash searches the directories listed in the value of the $PATH variable for a file that matches the command's name. This search is relatively "expensive" so, for better performance, bash keeps a table of commands that it has already looked up, known as a hash table, which it consults before scanning all the $PATH directories. There's more about it here if you scroll down to hash.