bash script variables weird results when using cp

Question

If I use cp inside a bash script the copied file will have weird charachters around the destination filename. The destination name comes from the results of an operation, it's put inside a variable, and echoing the variable shows normal output.

The objective is to name a file after a string.

    #!/bin/bash
    newname=`cat outputfile | grep 'hostname ' | sed 's/hostname //g'
    newecho=`echo $newname`
    echo $newecho
    cp outputfile "$newecho"

If I launch the script the echo looks ok

    $ ./rename.sh
    mo-swc-56001

However the file is named differently

    ~$ ls
    'mo-swc-56001'$'\r'

As you can see the file contains extra charachters which the echo does not show.

Edit: the newline of the file is like this

    # file outputfile
    outputfile: ASCII text, with CRLF, CR line terminators

I tried in every possible way to get rid of the ^M charachter but this is an example of the hundreds of attempts

    # cat outputfile | grep 'hostname ' | sed 's/hostname //g' | cat -v
    mo-swc-56001^M

    # cat outputfile | grep 'hostname ' | sed 's/hostname //g' | cat -v |  sed 's/\r//g' | cat -v
    mo-swc-56001^M

This newline will stay there. Any ideas?

Edit: crazy, the only way is to perform a dos2unix on the output...

Possible duplicate of [How to trim whitespace from a Bash variable?](https://stackoverflow.com/questions/369758/how-to-trim-whitespace-from-a-bash-variable) — user2653663, Sep 11 '19 at 21:02

RavinderSingh13 · Accepted Answer · 2019-09-12T02:01:23.030

0

Looks like your outputfile has \r characters in it, so you could add logic there to remove them and give it a try then.

#!/bin/bash
##remove control M first from outputfile  by tr command.
tr -d '\r' < outputfile  > temp && mv temp outputfile
newname=$(sed 's/hostname //g' outputfile)
newecho=`echo $newname`
echo $newecho
cp outputfile "$newecho"

edited Sep 12 '19 at 02:01

answered Sep 11 '19 at 15:11

RavinderSingh13

130,504
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@James Biffi, Could you please do let me know if this helps you? – RavinderSingh13 Sep 11 '19 at 16:52
I added some details in the question, there's a newline charachter that I can't get rid of. – James Biffi Sep 11 '19 at 20:54
@JamesBiffi, please check my EDIT command and let me know if that helps you? – RavinderSingh13 Sep 12 '19 at 02:01

score 0 · Answer 2 · answered Sep 12 '19 at 11:11

0

The only way was to use dos2unix

answered Sep 12 '19 at 11:11

James Biffi

47
5

bash script variables weird results when using cp

2 Answers2