Portable and efficient way to add text after pattern


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Portable and efficient way to add text after pattern
# 1  
Old 06-24-2018
Portable and efficient way to add text after pattern

Shell: sh/bash
OS: Linux (all unix flavors)

Suppose i have a variable with this content:

Code:
ArgZ='
import os
import sys
MySpecialpath = os.path.abspath(sys.argv[0])
#
'
ArgZB='#REGEN
#REGEN
#REGEN
'

I want to add this text to a file/script, only under the following conditions:

1. First, scan the file/script and verify that the first 2 lines of the ArgZ variable dont already exist in it. Meaning, make sure the exact patterns of "^import os$" and "^import sys$" aren't anywhere in the script. If they are, remove them.

2. Add the content of ArgZ and ArgZB only after the last line in the file/script that begins with an "import".

3. If there are no lines in the file/script that has an import, add the content of ArgZ and ArgZB to the top of the file/script right under the "#\!" line.

4. If a "#!" line does not exist, simply add the content of ArgZ and ArgZB to the top of the file/script.

So for example, if i have a file/script like the below:

Code:
#!/usr/bin/env python2.7

import sys
import time
import re
import os.path
from bisect import bisect_left

the code i'm looking for should make the output look like this:


Code:
#!/usr/bin/env python2.7

import os
import sys
MySpecialpath = os.path.abspath(sys.argv[0])
#
#REGEN
#REGEN
#REGEN
from bisect import bisect_left

or like this:

Code:
import os
import sys
MySpecialpath = os.path.abspath(sys.argv[0])
#
#REGEN
#REGEN
#REGEN
from bisect import bisect_left

what i was doing was greatly inefficient:

Code:
TheScript=$(cat file/script)
printf '%s\n' "${ArgsZ}""${ArgsZB}""${TheScript}"

There's no logic here and im just adding the content to the beginning of the file/script. I want some logic applied to this.
# 2  
Old 06-24-2018
Hi,

Maybe something like as :
Code:
awk -vArgz="$ArgZ" -vArgZB="$ArgZB" 'BEGIN{split(Argz,A,"\n")}
FNR == 1 {Line=0}
FNR == 1 && $0 ~ /^#!/ {Line=FNR}
$0 == A[2] || $0 == A[3]{next}
/^import/ {Line=FNR}
{B[FNR]=$0}
END{B[Line]=B[Line] Argz ArgZB;for (ll in B){print B[ll]}}' file

With your file example:
Code:
#!/usr/bin/env python2.7

import time
import re
import os.path
import os
import sys
MySpecialpath = os.path.abspath(sys.argv[0])
#
#REGEN
#REGEN
#REGEN

from bisect import bisect_left

This awk reads the file once and only once.


Regards.
This User Gave Thanks to disedorgue For This Post:
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

awk to add text to matching pattern in field

In the awk I am trying to add :p.=? to the end of each $9 that matches the pattern NM_. The below executes andis close but I can not seem to figure out why the :p.=? repeats in the split as in the green in the current output. I have added comments as well. Thank you :). file ... (4 Replies)
Discussion started by: cmccabe
4 Replies

2. Shell Programming and Scripting

Efficient awk way to add numbers in line fields

data.now: blah1,dah,blaha,sweet,games.log,5297484456,nagios-toin,529748456,on__host=93 SERVICE__ALERT_=51 Warning___The__results__of__service=16 Warning___on__host=92 Auto_save__of__retention__data__completed=1 Warning___Return=68 PASSIVE__SERVICE__CHECK_=53 ,1026--1313,1... (12 Replies)
Discussion started by: SkySmart
12 Replies

3. Shell Programming and Scripting

Efficient way to search array in text file by awk

I have one array SPLNO with approx 10k numbers.Now i want to search the subscriber number from MDN.TXT file (containing approx 1.5 lac record)from the array.if subscriber number found in array it will perform below operation.my issue is that it's taking more time because for one number it's search... (6 Replies)
Discussion started by: siramitsharma
6 Replies

4. Shell Programming and Scripting

Most efficient method to extract values from text files

I have a list of files defined in a single file , one on each line.(No.of files may wary each time) eg. content of ETL_LOOKUP.dat /data/project/randomname /data/project/ramname /data/project/raname /data/project/radomname /data/project/raame /data/project/andomname size of these... (5 Replies)
Discussion started by: h0x0r21
5 Replies

5. Shell Programming and Scripting

To add a new line with specific text after the pattern is found using sed

hi guys, im trying to add the following line in my xml file <dbrollbacksegs <oa_var="s_db_rollback_segs">NOROLLBACK</dbrollbacksegs> when ever i find the following line <dbsharedpool oa_var="s_dbsharedpool_size">300000000</dbsharedpool> I have succedded till adding a new line... (1 Reply)
Discussion started by: smarlaku
1 Replies

6. Shell Programming and Scripting

Efficient population of array from text file

Hi, I am trying to populate an array with data from a text file. I have a working method using awk but it is too slow and inefficent. See below. The text file has 70,000 lines. As awk is a line editor it reads each line of the file until it gets to the required line and then processes it.... (3 Replies)
Discussion started by: carlr
3 Replies

7. Homework & Coursework Questions

Efficient Text File Writing

Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted! 1. The problem statement, all variables and given/known data: Write a template main.c file via shell script to make it easier for yourself later. The issue here isn't writing... (2 Replies)
Discussion started by: george3isme
2 Replies

8. Shell Programming and Scripting

sed: Find start of pattern and extract text to end of line, including the pattern

This is my first post, please be nice. I have tried to google and read different tutorials. The task at hand is: Input file input.txt (example) abc123defhij-E-1234jslo 456ujs-W-abXjklp From this file the task is to grep the -E- and -W- strings that are unique and write a new file... (5 Replies)
Discussion started by: TestTomas
5 Replies

9. Shell Programming and Scripting

process text between pattern and print other text

Hi All, The file has the following. =========start of file=== This is a file containing employee info START name john id 123 date 12/1/09 END START name sam id 4234 date 12/1/08 resigned END (9 Replies)
Discussion started by: vlinet
9 Replies

10. Shell Programming and Scripting

Sed: add text if pattern not found

Hello, I would like to add the line TIMEZONE="CET" if the pattern TIMEZONE is not found between the range <JOB and JOB> : Example: Src file: <!DOCTYPE DEFTABLE SYSTEM "deftable.dtd"> <DEFTABLE > <JOB TASKTYPE="Job" TIMEFROM="0030" TIMEZONE="CET" </JOB> <JOB... (5 Replies)
Discussion started by: mutunzi
5 Replies
Login or Register to Ask a Question