CODEWITHSUNDEEP
shellunix
Luis Meléndez
Luis Meléndez

Reputation: 23

How can I append a string on a specific column on the lines that match a condition on a txt file using shell scripting?

I have a text file with a bunch of serial numbers and they're supposed to be 16 characters long. But some of the records were damaged and are 13 characters long. I want to add 3 zeros at the beginning of every record that has 13 characters long.

Note: The serial numbers doesn't start at the beginning of the line, they all start at the column 15 of every line.

My file currently looks like this:

1:CCCC:CC: :C:**0000000999993**:   :CCC:             :          
1:CCCC:CC: :C:**0000000999994**:   :CCC:             :          
1:CCCC:CC: :C:**0000000999995**:   :CCC:             :          
1:CCCC:CC: :C:**0000000000170891**:   :CCC:             :
1:CCCC:CC: :C:**0000000000170892**:   :CCC:             :      
1:CCCC:CC: :C:**0000000000170893**:   :CCC:             :

And the output should be:

1:CCCC:CC: :C:**0000000000999993**:   :CCC:             :          
1:CCCC:CC: :C:**0000000000999994**:   :CCC:             :          
1:CCCC:CC: :C:**0000000000999995**:   :CCC:             :          
1:CCCC:CC: :C:**0000000000170891**:   :CCC:             :
1:CCCC:CC: :C:**0000000000170892**:   :CCC:             :      
1:CCCC:CC: :C:**0000000000170893**:   :CCC:             :

This is the code I made to get the records that are shortened:

#!/bin/bash
i=1
for OUTPUT in $*(cut -c15-30 file.txt)
do
   if [[ ${#OUTPUT} == 13 ]]
   then 
          echo $OUTPUT
          echo $i
          i=$((i+1))
    
   fi
done

The txt file has more than 50,000 records so I can't change them manually.

Upvotes: 0

Views: 99

Answers (4)

M. Nejat Aydin
M. Nejat Aydin

Reputation: 10123

This sed one-liner should do the job:

sed 's/^\(.\{14\}\)\([0-9]\{13\}[^0-9]\)/\1000\2/' file

This assumes serial numbers consist of decimal digits only and trusts that they all start at the 15th character of the line.

Or, an awk solution:

awk 'BEGIN { FS=OFS=":" } length($6) == 13 { $6 = "000" $6 } 1 ' file

This one only checks if the length of the sixth field is 13 and trusts that sixth field is the serial number field.

Upvotes: 1

markp-fuso
markp-fuso

Reputation: 34484

One awk idea that replaces all of OP's current code:

awk '
BEGIN         { FS=OFS=":" }                # set input/output field delimiter to ":"
length($6)<16 { $6=sprintf("%016d",$6) }    # if length of 6th field < 16 then left-pad the field with 0's to length of 16
1                                           # print current line
' file.txt

This generates:

1:6822:26: :A:0000000000999993:DIS:14516E : :01: : : ::0529483733710: : :
1:6822:26: :A:0000000000999994:MAT:13L324 : :01: : : :: : : :
1:6822:26: :A:0000000000999995:CAT:P13WFB : :01: : : ::0529483697940: : :
1:6822:26: :3:0000000000170891: :AZDG-2 :0000003999:01:0000000000: : :: : : :
1:6822:26: :3:0000000000170892: :AZDG-3 :0000003999:01:0000000000: : :: : : :
1:6822:26: :3:0000000000170893: :AZDG-4 :0000003999:01:0000000000: : :: : : :

Upvotes: 1

Diego Torres Milano
Diego Torres Milano

Reputation: 69218

Another alternative

awk -v{O,}FS=: '{$6=gensub(" ", "0", "g", sprintf("%16s", gensub(" ", "", "g", $6)))}1'

result

1:6822:26: :A:0000000000999993:DIS:14516E : :01: : : ::0529483733710: : :
1:6822:26: :A:0000000000999994:MAT:13L324 : :01: : : :: : : :
1:6822:26: :A:0000000000999995:CAT:P13WFB : :01: : : ::0529483697940: : :
1:6822:26: :3:0000000000170891: :AZDG-2 :0000003999:01:0000000000: : :: : : :
1:6822:26: :3:0000000000170892: :AZDG-3 :0000003999:01:0000000000: : :: : : :
1:6822:26: :3:0000000000170893: :AZDG-4 :0000003999:01:0000000000: : :: : : :

Upvotes: 0

tink
tink

Reputation: 15214

I took the liberty to tack a : on ...

$ awk '{if(length($2)<19){$2=gensub(/^(:.:)/,"\\1000","1",$2)":"}}1' file.txt 
1:6822:26: :A:0000000000999993: :DIS:14516E : :01: : : ::0529483733710: : :
1:6822:26: :A:0000000000999994: :MAT:13L324 : :01: : : :: : : :
1:6822:26: :A:0000000000999995: :CAT:P13WFB : :01: : : ::0529483697940: : :
1:6822:26: :3:0000000000170891: :AZDG-2 :0000003999:01:0000000000: : :: : : :
1:6822:26: :3:0000000000170892: :AZDG-3 :0000003999:01:0000000000: : :: : : :
1:6822:26: :3:0000000000170893: :AZDG-4 :0000003999:01:0000000000: : :: : : :

If that's not what you want, use this: awk '{if(length($2)<19){$2=gensub(/^(:.:)/,"\\1000","1",$2)}}1' file.txt

Upvotes: 0

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