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Full Discussion: Removing lines from a file
Top Forums Shell Programming and Scripting Removing lines from a file Post 303013335 by Don Cragun on Monday 19th of February 2018 08:56:12 PM
Old 02-19-2018
What are you trying to match with . in the basic regular expressions you are creating to be used as addresses in sed? What characters does a <period> in a BRE match? Each of the following sed commands will remove every line in the current sample /tmp/wrk file you now have in post #1 in this thread.
Code:
sed -i /.212/d /tmp/wrk
sed -i /.126/d /tmp/wrk
sed -i /.260/d /tmp/wrk
sed -i /.201/d /tmp/wrk
sed -i /.016/d /tmp/wrk

Your last script in post #3, update #3 doesn't currently use .212 or .260; but it does use the other three.

Maybe you'd like to try the following replacement for that script and see if it works any better for you:
Code:
for day in {1..207} {282..356}
do    
  if (( day < 10 )); then
    daytag="00$day" 
  elif (( day < 100 )); then
    daytag="0$day" 
  else
    daytag="$day"
  fi
  rgx="/[.]${daytag}$/d" 
  echo "sed -i \"$rgx\" /tmp/wrk"
  sed -i "$rgx" /tmp/wrk  
done

PS: Note that editing a file a few hundred times with sed is grossly inefficient. You would probably be better off using ed or ex to edit your file once feeding global editing commands to one invocation of that editor and after all of the updates have been completed, add a w command at the end to write all of the updates back to your input file. Running ed once instead of running sed about 290 times will be MUCH faster.
Last edited by Don Cragun; 02-19-2018 at 10:07 PM.. Reason: Add PS.
 

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LEARN ABOUT REDHAT

prunehistory

PRUNEHISTORY(8) 					      System Manager's Manual						   PRUNEHISTORY(8)

NAME

       prunehistory - remove file names from Usenet history file

SYNOPSIS

       prunehistory [ -f filename ] [ -p ]

DESCRIPTION

       Prunehistory  modifies  the  history(5)	text file to ``remove'' a set of filenames from it.  The filenames are removed by overwriting them
       with spaces, so that the size and position of any following entries does not change.

       Prunehistory reads the standard input.  The input is taken as a set of lines.  Blank lines and lines starting with a  number  sign  (``#'')
       are ignored.  All other lines are should consist of a Message-ID followed by zero or more filenames.

       The  Message-ID	is  used as the dbz(3) key to get an offset into the text file.  If no filenames are mentioned on the input line, then all
       filenames in the text are ``removed.''  If any filenames are mentioned, they are converted into the history file notation.  If they  appear
       in the line for the specified Message-ID then they are removed.

       Since innd(8) only appends to the text file, prunehistory does not need to have any interaction with it.

OPTIONS

       -p     Prunehistory will normally complain about lines that do not follow the correct format.  If the ``-p'' flag is used, then the program
	      will silently print any invalid lines on its standard output.  (Blank lines and comment lines are also passed through.)  This can be
	      useful when prunehistory is used as a filter for other programs such as reap.

       -f     The default name of the history file is <pathdb in inn.conf>/history; to specify a different name, use the ``-f'' flag.

HISTORY

       Written by Rich $alz <rsalz@uunet.uu.net> for InterNetNews.  This is revision 1.7, dated 1998/04/09.

SEE ALSO

       dbz(3), history(5), inn.conf(5), innd(8).

																   PRUNEHISTORY(8)
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