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Full Discussion: delete lines matching a regular expression
Top Forums UNIX for Dummies Questions & Answers delete lines matching a regular expression Post 302604693 by pathunkathunk on Monday 5th of March 2012 05:11:53 PM
Old 03-05-2012
delete lines matching a regular expression
I have a very large file (over 700 million lines) that has some lines that I need to delete. An example of 5 lines of the file:

HS4_80:8:2303:19153:193032 153 k80:138891 [...]
HS4_80:8:2105:5544:43174 89 k88:81949 [...]
165 k88:81949 323 0 * = 323 0 [...]
HS4_80:8:2105:5544:19502 73 k64:351700 [...]
HS4_80:8:2303:19154:108202 137 k72:245019 [...]

Two questions:
1. How can I confirm that the first character in line 3 above (beginning with 165) is a tab, so that I might use that as a regular expression, i.e. delete all lines that begin with tab. (Not all the lines I want to keep begin with HS4, nor do all the lines I want to delete begin with 165).

1. Assuming I find the right regular expression, how do I create a new file that is exactly the same, minus the lines I want to delete (like line 3 above)?

I'm a biologist who is new to programming. I know a lot more than I did a few weeks ago but it's slow going...so thanks for any help!
 

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LEARN ABOUT OPENSOLARIS

winsdelln

insdelln(3XCURSES)					  X/Open Curses Library Functions					insdelln(3XCURSES)

NAME

       insdelln, winsdelln - insert/delete lines to/from the window

SYNOPSIS

       cc [ flag... ] file... -I /usr/xpg4/include  -L	/usr/xpg4/lib 
	-R  /usr/xpg4/lib  -lcurses  [ library... ]

       c89 [ flag... ] file... -lcurses [ library... ]

       #include <curses.h>

       int insdelln(int n);

       int winsdelln(WINDOW *win, int n);

PARAMETERS

       n      Is the number of lines to insert or delete (positive n inserts; negative n deletes).

       win    Is a pointer to the window in which to insert or delete a line.

DESCRIPTION

       The  insdelln()	and  winsdelln() functions insert or delete blank  lines  in stdscr or win, respectively.  When n is positive, n lines are
       added before the current line  and the bottom n lines are lost; when n is negative, n lines  are deleted starting with  the  current  line,
       the remaining lines are moved up,  and the bottom n lines are cleared. The position of the cursor does not change.

RETURN VALUES

       On success, these functions return OK. Otherwise, they return ERR.

ERRORS

       None.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Unsafe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       deleteln(3XCURSES), insertln(3XCURSES), libcurses(3XCURSES), attributes(5), standards(5)

SunOS 5.11							    5 Jun 2002							insdelln(3XCURSES)
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