Re: Bash shell script issue

[Kipton Moravec <kipton_moravec@yahoo.com>]

As I said I am new to shell scripting. I have been programming microcontrollers, bare bones with no OS for most of the past 40 years. 


dalkmora@DALM0048 ~/walnut/dp2b_walnut_customer_flextronics/walnut 
$ od -cx testconvert1.sh 
0000000   #   !   /   b   i   n   /   b   a   s   h  \r  \n   e   c   h 
2123    622f    6e69    622f    7361    0d68    650a    6863 
0000020   o       $   P   W   D  \r  \n   p   r   o   j   e   c   t   _ 
206f    5024    4457    0a0d    7270    6a6f    6365    5f74 
0000040   r   o   o   t   =   $   P   W   D  \r  \n   e   c   h   o 
6f72    746f    243d    5750    0d44    650a    6863    206f 
0000060   $   p   r   o   j   e   c   t   _   r   o   o   t  \r  \n   x 
7024    6f72    656a    7463    725f    6f6f    0d74    780a 
0000100   =   $   {   p   r   o   j   e   c   t   _   r   o   o   t   } 
243d    707b    6f72    656a    7463    725f    6f6f    7d74 
0000120   /   t   o   o   l   s  \r  \n   e   c   h   o       $   x  \r 
742f    6f6f    736c    0a0d    6365    6f68    2420    0d78 
0000140  \n   e   c   h   o       $   {   x   }       |       c   a   t 
650a    6863    206f    7b24    7d78    7c20    6320    7461 
0000160       -   A 
2d20    0041 
0000163 

Shows there is not "careless editing". 



So "Insufficient quoting" means nothing to me. How should it be? I was taking the example from a shell script I found. 


So I added quoting on the echo:

#!/bin/bash 
echo "$PWD" 
project_root=$PWD 
echo "$project_root" 
x=${project_root}/tools 
echo "$x" 
echo "${x}" | cat -A

dalkmora@DALM0048 ~/walnut/dp2b_walnut_customer_flextronics/walnut 
$ ./testconvert1.sh 
/home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut 
/home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut 
/toolsdalkmora/walnut/dp2b_walnut_customer_flextronics/walnut 
/home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut^M/tools^M$ 

No difference. 


So maybe in the commands?


#!/bin/bash 
echo "$PWD" 
project_root="$PWD" 
echo "$project_root" 
x="${project_root}"/tools 
echo "$x" 
echo "${x}" | cat -A

dalkmora@DALM0048 ~/walnut/dp2b_walnut_customer_flextronics/walnut 
$ ./testconvert1.sh 
/home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut 
/home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut 
/toolsdalkmora/walnut/dp2b_walnut_customer_flextronics/walnut 
/home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut^M/tools^M$ 

Again no difference. 

So finally I looked up d2u


dalkmora@DALM0048 ~/walnut/dp2b_walnut_customer_flextronics/walnut 
$ d2u testconvert1.sh 
dos2unix: converting file testconvert1.sh to Unix format... 

dalkmora@DALM0048 ~/walnut/dp2b_walnut_customer_flextronics/walnut 
$ ./testconvert1.sh 
/home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut 
/home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut 
/home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut/tools 
/home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut/tools$ 

That fixed it, but I still do not understand it. 

Why are there ^M (carriage return) in the middle of a line? I can understand the confusion at the end of the line. But there was none shown in the middle from od command.

Kip
 


----- Original Message -----
From: Eric Blake <eblake@redhat.com>
To: cygwin@cygwin.com; kipton_moravec@yahoo.com
Sent: Tuesday, September 6, 2016 8:21 PM
Subject: Re: Bash shell script issue

On 09/06/2016 05:36 PM, Kipton Moravec wrote:

> I this is the script: 
> #!/bin/bash 
> echo $PWD 

Insufficient quoting. This does not do the right thing if $PWD contains
spaces.  But not necessarily related to your problem at hand.

> project_root=$PWD 
> echo $project_root 

Again, insufficient quoting.

> x=${project_root}/tools 
> echo $x 

And again.

> echo ${x} | cat -A 
> 
> On original Windows 7 computer I get: 
> dalkmora@DALM0048 ~/walnut/dp2b_walnut_customer_flextronics/walnut 
> $ ./testconvert1.sh 
> /home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut 
> /home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut 
> /toolsdalkmora/walnut/dp2b_walnut_customer_flextronics/walnut 
> /home/dalkmora/walnut/dp2b_walnut_customer_flextronics/walnut^M/tools^M$ 

The carriage returns are likely a product of you editing the file in
text mode (Windows notepad is notorious for this, but many other native
programs do likewise), but trying to execute the script in binary mode
(the default, if you do not use 'set -o igncr').



> What am I doing wrong or is this an error? 
> Where do the carriage returns (^M) come from, and how do I get rid of them? 

d2u /path/to/your/script

to remove all the carriage returns from your careless editing. Once they
are gone, then you don't need the 'igncr' crutch to tell bash to go into
text mode.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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