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Replace string works on command-line but fails when run from shell script

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# 1  
Old 09-03-2019
Replace string works on command-line but fails when run from shell script
I wish to replace "\\n" with a single white space.

The below does the job on command-line:

Code:
$ echo '/fin/app/scripts\\n/fin/app/01/sql' | sed -e 's#\\\\n# #g';
/fin/app/scripts /fin/app/01/sql

However, when i have the same code to a shell script it is not able to get me the same output: See below:

Code:
$ more check.sh
str=`echo "$1" | sed -e 's#\\\\n# #g'`
echo $str>check.now

Code:
$ bash -x ./check.sh '/fin/app/01/scripts\\n/fin/app/01/sql'
++ echo '/fin/app/01/scripts\\n/fin/app/01/sql'
++ sed -e 's#\\n# #g'
+ str='/fin/app/01/scripts\ /fin/app/01/sql'
+ echo '/fin/app/01/scripts\' /fin/app/01/sql

Code:
$ more check.now 
/fin/app/01/scripts\ /fin/app/01/INFENG/sql

We see the issue with "/fin/app/01/scripts\" the trailing \ at the end of the first string.

Note: I have to pass the argument to check.sh script strictly in single quotes only.

Requesting suggestions and explanations for this issue.
Last edited by mohtashims; 09-03-2019 at 09:20 AM..
# 2  
Old 09-03-2019
Code:
$ cat check.sh
str=`echo $1  | sed -e 's#[\][\]n# #g'`
echo $str>check.now
$ bash -x ./check.sh '/fin/app/01/scripts\\n/fin/app/01/sql'
++ echo '/fin/app/01/scripts\\n/fin/app/01/sql'
++ sed -e 's#[\][\]n# #g'
+ str='/fin/app/01/scripts /fin/app/01/sql'
+ echo /fin/app/01/scripts /fin/app/01/sql
$ more check.now
/fin/app/01/scripts /fin/app/01/sql
$

# 3  
Old 09-03-2019
I think you suffer from the \ handling within `backticks`
Demonstration:
Code:
cat check.sh
str=`echo "$1" | sed -e 's#\\\\n# #g'`
echo "$str"
str=$(echo "$1" | sed -e 's#\\\\n# #g')
echo "$str"

Code:
bash ./check.sh '/fin/app/01/scripts\\n/fin/app/01/sql'
/fin/app/01/scripts\ /fin/app/01/sql
/fin/app/01/scripts /fin/app/01/sql

# 4  
Old 09-03-2019
You could try something like this:
Longhand OSX 10.14.3, default bash terminal using 'dash'...
Code:
Last login: Tue Sep  3 18:18:39 on ttys000
AMIGA:amiga~> dash
AMIGA:\u\w> text='oiweroiweroi oieurowir lkj
> asdkjd pqowepom,xcm909184 ;lk
> 0912830980n kjhksjdfkj oizxc
> 
> '
AMIGA:\u\w> echo "${text}"       
oiweroiweroi oieurowir lkj
asdkjd pqowepom,xcm909184 ;lk
0912830980n kjhksjdfkj oizxc


AMIGA:\u\w> text1=$( echo $text )
AMIGA:\u\w> echo "${text1}"
oiweroiweroi oieurowir lkj asdkjd pqowepom,xcm909184 ;lk 0912830980n kjhksjdfkj oizxc
AMIGA:\u\w> exit
AMIGA:amiga~> _

# 5  
Old 09-03-2019
Why sed? Try "parameter expansion":
Code:
echo ${1//\\\\n/ }
/fin/app/01/scripts /fin/app/01/sql

# 6  
Old 09-03-2019
Fully POSIX compliant using OP's parameters:
Code:
#!/usr/local/bin/dash
# check.sh
# $1 is '/fin/app/01/scripts\\n/fin/app/01/sql'

text=$( echo $( echo $1 ) )
echo $text

Results using as before...
Code:
Last login: Tue Sep  3 23:00:12 on ttys000
AMIGA:amiga~> cd Desktop/Code/Shell
AMIGA:amiga~/Desktop/Code/Shell> ./check.sh '/fin/app/01/scripts\\n/fin/app/01/sql'
/fin/app/01/scripts /fin/app/01/sql
AMIGA:amiga~/Desktop/Code/Shell> _

# 7  
Old 09-04-2019
Quote:
Originally Posted by RudiC
Why sed? Try "parameter expansion":
Code:
echo ${1//\\\\n/ }
/fin/app/01/scripts /fin/app/01/sql

Sorry, but it does not give correct output. See below:

Quote:
bash -x ./check.sh '/fin/app/01/scripts\\n/fin/app/01/sql'
++ echo '/fin/app/01/scripts\' /fin/app/01/sql
+ str='/fin/app/01/scripts\ /fin/app/01/sql'
+ echo '/fin/app/01/scripts\' /fin/app/01/sql
Look at the trailing \ after the first string /fin/app/01/scripts\

Code:
cat check.sh
str=`echo ${1//\\\\n/ }`
echo $str>check.row

--- Post updated at 05:11 AM ---

Quote:
Originally Posted by wisecracker
Fully POSIX compliant using OP's parameters:
Code:
#!/usr/local/bin/dash
# check.sh
# $1 is '/fin/app/01/scripts\\n/fin/app/01/sql'

text=$( echo $( echo $1 ) )
echo $text

Results using as before...
Code:
Last login: Tue Sep  3 23:00:12 on ttys000
AMIGA:amiga~> cd Desktop/Code/Shell
AMIGA:amiga~/Desktop/Code/Shell> ./check.sh '/fin/app/01/scripts\\n/fin/app/01/sql'
/fin/app/01/scripts /fin/app/01/sql
AMIGA:amiga~/Desktop/Code/Shell> _

This does not work for me. See my test below.

Code:
cat check.sh
str=$( echo $( echo $1 ) )
echo $str>check.row

Quote:
Results:
bash -x ./check.sh '/fin/app/01/scripts\\n/fin/app/01/sql'
+++ echo '/fin/app/01/scripts\\n/fin/app/01/sql'
++ echo '/fin/app/01/scripts\\n/fin/app/01/sql'
+ str='/fin/app/01/scripts\\n/fin/app/01/sql'
+ echo '/fin/app/01/scripts\\n/fin/app/01/sql'
Also, I intend to run this on ksh shell as well.

--- Post updated at 05:13 AM ---

Quote:
Originally Posted by wisecracker
You could try something like this:
Longhand OSX 10.14.3, default bash terminal using 'dash'...
Code:
Last login: Tue Sep  3 18:18:39 on ttys000
AMIGA:amiga~> dash
AMIGA:\u\w> text='oiweroiweroi oieurowir lkj
> asdkjd pqowepom,xcm909184 ;lk
> 0912830980n kjhksjdfkj oizxc
> 
> '
AMIGA:\u\w> echo "${text}"       
oiweroiweroi oieurowir lkj
asdkjd pqowepom,xcm909184 ;lk
0912830980n kjhksjdfkj oizxc


AMIGA:\u\w> text1=$( echo $text )
AMIGA:\u\w> echo "${text1}"
oiweroiweroi oieurowir lkj asdkjd pqowepom,xcm909184 ;lk 0912830980n kjhksjdfkj oizxc
AMIGA:\u\w> exit
AMIGA:amiga~> _

This is not a new line but delimiter of type string "\\n" i guess.

--- Post updated at 05:26 AM ---

Quote:
Originally Posted by MadeInGermany
I think you suffer from the \ handling within `backticks`
Demonstration:
Code:
cat check.sh
str=`echo "$1" | sed -e 's#\\\\n# #g'`
echo "$str"
str=$(echo "$1" | sed -e 's#\\\\n# #g')
echo "$str"

Code:
bash ./check.sh '/fin/app/01/scripts\\n/fin/app/01/sql'
/fin/app/01/scripts\ /fin/app/01/sql
/fin/app/01/scripts /fin/app/01/sql

@MadeInGermany you seem to have highlighted the core point of this issue.

However, I wanted to know if there is a solution for ksh shell on AiX with backticks ? A non-sed solution would also do. Thank you!!
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