Read line from the file and append it to each row

Shell Programming and Scripting
1

Hi All,

We have a file in the following format:

 0.010000  $  ITI   11 LV2         $    40456211  $
 0.135000  $  ITI   11 LV1         $    40512211  $
 1.215600  $  ITI   11 ITI3         $    41406211  $
 24/05/2014 14:05:02
  
 0.030000  $  ITI   11 LV2       $    40456211  $
 0.115000  $  ITI   11 LV1       $    40512211  $
 1.265600  $  ITI   11 ITI3       $    41406211  $
 24/05/2014 14:10:02
 0.000000  $  ITI   11 LV2         $    40456211  $
 0.145000  $  ITI   11 LV1         $    40512211  $
 1.215600  $  ITI   11 ITI3         $    41406211  $
  24/05/2014 14:15:02

We want to read the time given in some rows and prepend them as first column in each row preceding it. We will also remove empty/blank rows. So it will look something like this.

24/05/2014 14:05:02 $  0.010000  $  ITI   11 LV2       $    40456211  $
  24/05/2014 14:05:02 $  0.135000  $  ITI   11 LV1       $    40512211  $
  24/05/2014 14:05:02 $  1.215600  $  ITI   11 ITI3       $    41406211  $
  24/05/2014 14:10:02 $  0.030000  $  ITI   11 LV2       $    40456211  $
  24/05/2014 14:10:02 $  0.115000  $  ITI   11 LV1       $    40512211  $
  24/05/2014 14:10:02 $  1.265600  $  ITI   11 ITI3       $    41406211  $
  24/05/2014 14:15:02 $  0.000000  $  ITI   11 LV2       $    40456211  $
  24/05/2014 14:15:02 $  0.145000  $  ITI   11 LV1       $    40512211  $
  24/05/2014 14:15:02 $  1.215600  $  ITI   11 ITI3       $    41406211  $

Thanks for your help.

2 
$ awk 'NF==2{$1=$1;gsub(/\*/,$0 c,s);print s;s="";next}NF{$1=$1;s = s ? s ORS "*"$0 : "*"$0 }' c=' $ ' file

24/05/2014 14:05:02 $ 0.010000 $ ITI 11 LV2 $ 40456211 $
24/05/2014 14:05:02 $ 0.135000 $ ITI 11 LV1 $ 40512211 $
24/05/2014 14:05:02 $ 1.215600 $ ITI 11 ITI3 $ 41406211 $
24/05/2014 14:10:02 $ 0.030000 $ ITI 11 LV2 $ 40456211 $
24/05/2014 14:10:02 $ 0.115000 $ ITI 11 LV1 $ 40512211 $
24/05/2014 14:10:02 $ 1.265600 $ ITI 11 ITI3 $ 41406211 $
24/05/2014 14:15:02 $ 0.000000 $ ITI 11 LV2 $ 40456211 $
24/05/2014 14:15:02 $ 0.145000 $ ITI 11 LV1 $ 40512211 $
24/05/2014 14:15:02 $ 1.215600 $ ITI 11 ITI3 $ 41406211 $

This keeps your original formatting

$ awk 'NF==2{gsub(/\*/,$0 c,s);print s;s="";next}NF{s = s ? s ORS "*"$0 : "*"$0 }' c=' $ ' file

---------- Post updated at 05:45 PM ---------- Previous update was at 05:40 PM ----------

OR

$ awk 'NF==2{d=$0;next}NF{print d,"$",$0}' <(tac file) | tac
3

could you explain that:

gsub(/\*/,$0 c,s)

who's "s" and "c" ???

4

Hi protocomm,

  1. Variable s saves every line $0 where NF is greater than 0 NF{.. , with ORS ,so blank line are skipped here.

  2. I used * , inorder to replace it with coming date and time where number of fields equal to 2 NF==2 .

  3. Once number of fields NF equal to 2, substitute $0 along with variable c for all * in variable s . Global subsitution using gsub function.

Just see difference when variable c is set to ' $ ' 

$ awk 'NF==2{$1=$1;gsub(/\*/,$0 c,s);print s;s="";next}NF{$1=$1;s = s ? s ORS "*"$0 : "*"$0 }' c=' $ ' file
24/05/2014 14:05:02 $ 0.010000 $ ITI 11 LV2 $ 40456211 $
24/05/2014 14:05:02 $ 0.135000 $ ITI 11 LV1 $ 40512211 $
....

Here variable c is empty

$ awk 'NF==2{$1=$1;gsub(/\*/,$0 c,s);print s;s="";next}NF{$1=$1;s = s ? s ORS "*"$0 : "*"$0 }' c='' file
24/05/2014 14:05:020.010000 $ ITI 11 LV2 $ 40456211 $
24/05/2014 14:05:020.135000 $ ITI 11 LV1 $ 40512211 $
....
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