Linux Shell "Variable" to use for File Input "<"

Question

I'm trying to make mysql database input from a file. But the db filename will be coming from the variable filename= /file/path/name.sql. But when input using < it is showing ambiguous redirect error.

My full script is:

filename= /var/backup/mydatabase.sql
echo $filename
mysql -uxxxx -pxxxx -hxxxx databasename < $filename

And the output is:

/var/backup/mydatabase.sql

./myscript.sh: line 3: $filename: ambiguous redirect

Please note followings:

Please assume the filename variable is needed for some reason
I'm a root user

So my question here is:

How to use shell variables for file input purpose?

There's really no reason to be running the mysql client as root... — Mark Reed
– Mark Reed, Commented Nov 21, 2012 at 2:42
Oh really! Don't do anything as root that is not absolutely necessary. — Jonathan Leffler
– Jonathan Leffler, Commented Nov 21, 2012 at 4:04
Also, please do not edit the question so as to destroy the meaningfulness of the answer. Accept the answer instead. — Jonathan Leffler
– Jonathan Leffler, Commented Nov 21, 2012 at 4:05

kev · Accepted Answer · 2012-11-21 02:54:14Z

3

filename= /var/backup/mydatabase.sql
         ^

Spaces around = are not allowed when you define a variable.
Please remove the space after =.

./myscript.sh: line 3: $filename: ambiguous redirect

This error message tells your that $filename may expand to multi-words.
Please double-quote "$filename".

Make sure that script file doesn't contain any invisible ctrl-chars at end of line.
Use command xxd myscript.sh to check.

edited Nov 21, 2012 at 2:54

answered Nov 21, 2012 at 2:34

kev

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5 Comments

Mark Reed Over a year ago

Yes. You are setting filename to nothing and then attempting to run /var/backup/mydatabase.sql as a command, which should produce an error message before the ambiguous redirect thing.

Mark Reed Over a year ago

Then you didn't do it right. The assignment should be filename=/var/backup/mydatabase.sql. No spaces anywhere. If you do that and still get an error, then you have either typoed the variable name in one of the two lines, or your simplified version of the problem is too simplified.

夏期劇場 Over a year ago

NO. Please see my output (i edited). The $filename is coming. Problem is not that.

Mark Reed Over a year ago

Is the filename really /var/backup/mydatabase.sql, or does it maybe have a space in it?

夏期劇場 Over a year ago

NO SPACE between :/ .. and not working also with this filename=/var/backup/mydatabase.sql :/

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