how to fix 3,359 pages with an incomplete URL, using grep, find and perl...

fixing embedded HTML tags in a large number of files

#  fixing BibleTech
#   BAD STRING, needs .net   a href="http://BibleTech" target

Updated html files some time ago, changing a URL or a path and accidently removed the domain from a large number of links...

      a href="http://BibleTech" target  

Have used perl to fix other broken or outdated URLs on the server:

#  fix-domains-dec-2017.sh:# find /home/luser/httpd/ -type f -name "*.html" -exec perl -pi -e 's$http://linuxmeister.net$http://johnmeister.com/linux$g' {} \;
#  fix-domains-dec-2017.sh:find /home/luser/httpd/ -type f -name "*.html" -exec perl -pi -e 's$linuxmeister.net$johnmeister.com/linux$g' {} \;
#  x-perl-find-fix-linuxmeister.net.txt:--> find . -type f -name '*.html' -exec perl -pi -e 's$linuxmeister.net$johnmeister.com/linux$g' {} \;
#  

 TESTING the command on a single file FIRST 

 first find a file in the current directory
 then  execute the perl string at the command line
 then check to see if it fixed it with a grep
 then open the test file with vi or more and make sure nothing else broke

 ------------------------------------------------
 look for and pick a file:
--> grep "a href=\"http://BibleTech\" target" *.html
Books-by-John.html:<a href="http://BibleTech" target="_blank">BibleTech</a>- Bible overview


 use find with perl to edit that ONE file:
  ------------------------------------------------
--> find . -type f -name The_Art_of_Linux_System_Administration.html \
         -exec perl -pi -e 's$a href=\"http://BibleTech\" target$a href=\"http://BibleTech.net\" target$g' {} \;
  
 use grep the file should NOT come up:
 ------------------------------------------------
--> grep "a href=\"http://BibleTech\" target" *.html
  
(SILENCE IS GOLDEN - remember the Philosophy of LINUX (UNIX)!)

 Then modify the find and perl string and run...

find . -type f -name *.html -exec perl -pi -e 's$a href=\"http://BibleTech\" target$a href=\"http://BibleTech.net\" target$g' {} \;


 Decided to first see how many files, and time the actions:
#  ------------------------------------------------
#  --> time find . -type f -name "*.html" -exec grep "a href=\"http://BibleTech\" target" {} \;  | wc -l
#  3359
#  
#  real    4m25.992s
#  user    0m56.230s
#  sys 0m23.291s
#  
#  ------------------------------------------------
#  --> time find . -type f -name "*.html" -exec perl -pi -e 's$a href=\"http://BibleTech\" target$a href=\"http://BibleTech.net\" target$g' {} \;
#  
#  real    8m40.815s
#  user    1m32.800s
#  sys 0m46.286s
#  
#  ------------------------------------------------
#  --> time find . -type f -name "*.html" -exec grep "a href=\"http://BibleTech\" target" {} \;  
#  
#  real    4m7.665s
#  user    0m54.618s
#  sys 0m23.934s
#  
#  ------------------------------------------------