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Bash and sed compatibility

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# 1  
Old 07-09-2013
Bug Bash and sed compatibility
Hi i am having a stange problem.
Basically for my sed script used within bash i can unly use a single Quote with sed '. (if i use " then i get command garbled error with sed )
The problem with this is BASH does not interprit variables within single quote ' so we cannot use any of the BASH variables in sed ?

Its frustrating me, please take a look at the sample

Sample 1[code]
Code:
#!/bin/bash
while read job_nm time
do
   for file in `cat jil_file_nm_list`
   do
      match=`grep $job_nm $file`
      if [ ! -z "$match" ]; then
         echo  match found
         sed "/^insert_job:[ ,\t]$job_nm/ a\
         test line 1 \
         test line2 " wr.sfa.apr.jil
      else
           echo match not found
      fi
   done
done < mxtm.out.sample

When i run this the error is
Code:
]
bash-3.2$ bash maxtime_bash.sh
match found
sed: command garbled: /^insert_job:[ ,\t]WR#cmd#sfa_2_1_xtrapr/ a test line 1 test line2
match not found
match not found
match not found

Sample 2

Code:
#!/bin/bash
while read job_nm time
do
for file in `cat jil_file_nm_list`
do
match=`grep $job_nm $file`
if [ ! -z "$match" ]; then
echo  match found
sed '/^insert_job:[ ,\t]$job_nm/ a\
test line 1 \
test line2 ' wr.sfa.apr.jil
else
       echo match not found
fi
done
done < mxtm.out.sample


When i run sample2 $job_nm is not evaluated !

Code:
+ sed '/^insert_job:[ ,\t]$job_nm/ a\
 test line 1 \
test line2 ' wr.sfa.apr.jil
/* delete_job: WR#cmd#sfa_2_1_xtrrdw_apr    job_type: c */


How do i fix scenario 2 or for that matter 1.



Moderator's Comments:
Mod Comment Next time : Please use code tags for you data and code
Last edited by vash; 07-09-2013 at 12:59 PM.. Reason: indent code after code tagging...
# 2  
Old 07-09-2013
Sed is not 'incompatible' with single or double quotes. Quotes no longer exist by the time sed gets the string. They do alter the interpretation of the string -- as you can see when it spits it back out in the error. It's putting it all on one line.

I think you need to remove the backslashes \ separating lines. Multi-line strings are actually valid in Bourne shell, but putting the backslashes there (inside double quotes) tells it to cram it all in one single line.

Single quotes, which escape nothing ever, just put in literal backslashes and split it across lines anyway.
# 3  
Old 07-09-2013
bash and sed
Corona
The multiline is for the sed the append command requires a new line after a

This will not solve my problem of resolving the job_nm variable any way would it ?
# 4  
Old 07-09-2013
Quote:
Originally Posted by vash
Corona
The multiline is for the sed the append command requires a new line
So remove the backslash, because, as stated above, they are preventing it from actually being multiple lines.

Code:
$ echo "a\
b\
c"

abc

$ echo "a
b
c"

a
b
c

$

Quote:
This will not solve my problem of resolving the job_nm variable any way would it ?
The problem is, simply, that variables do not expand inside single quotes.

Remove the \ from the double quotes and see if it works.
# 5  
Old 07-09-2013
sed bash
No removing \ from " dint work as sed complaining about command
here is a smaller version i am testing with

Code:
#!/bin/bash
var=WR#cmd#sfa_2_1_xtrapr
sed "/^insert_job:[ ,\t]$var/ a
> test line 1 " wr.sfa.apr.jil

bash-3.2$ bash expsn
sed: command garbled: /^insert_job:[ ,\t]$var/ a

---------- Post updated at 12:08 PM ---------- Previous update was at 12:07 PM ----------

Quote:
Originally Posted by Corona688
So remove the backslash, because, as stated above, they are preventing it from actually being multiple lines.

Corona - the \ is Used withn SED not BASH
i understand what you are tryign to say please see my code properly ..and i mentioned its th eSED that requires it not BASH ..

Code:
$ echo "a\
b\
c"
 
abc
 
$ echo "a
b
c"
 
a
b
c
 
$

The problem is, simply, that variables do not expand inside single quotes.

Remove the \ from the double quotes and see if it works.
# 6  
Old 07-09-2013
Does your sed command need the backslashes? You may need to double them up, then.

Code:
$ echo "a\\
b\\
c"

a\
b\
c

$

This User Gave Thanks to Corona688 For This Post:
vash
# 7  
Old 07-09-2013
Quote:
Originally Posted by Corona688
Does your sed command need the backslashes? You may need to double them up, then.

Code:
$ echo "a\\
b\\
c"
 
a\
b\
c
 
$

Thanks Thats it .. dint hit me untill i saw the solution .. dang ! thank you
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