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Top Forums Shell Programming and Scripting How to read n number of lines from a file Post 302360514 by varsha on Friday 9th of October 2009 07:15:29 AM
Old 10-09-2009
Data How to read n number of lines from a file

Hiii

I am very new to shell scripting.This is my data file
a.txt:
56
45.78
1000
11.23
76.89
45
34.56
23
3400
100
..........
Now i am must use shell scripting to read n number of lines from the file & from ts n number of lines i need to find greatest number among them & so on for rest of the file still end of the file...
For example from the above data file
I want to check for first 3(this must be user defined) lines & so on for largest number
The ouput for such a condition must be
for first set(i.e first 3 lines)
output is 1000
then 2nd set
output is 76.89
the 3rd set
output is 3400
& so on till end of my file..
.......
Help is greatly appreciatedSmilieSmilie
Thanks
 

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uniq(1) 						      General Commands Manual							   uniq(1)

Name
       uniq - report repeated lines in a file

Syntax
       uniq [-udc[+n][-n]] [input[output]]

Description
       The  command  reads  the  input	file comparing adjacent lines.	In the normal case, the second and succeeding copies of repeated lines are
       removed; the remainder is written on the output file.  Note that repeated lines must be adjacent in order to be found.  For further  infor-
       mation, see

Options
       The n arguments specify skipping an initial portion of each line in the comparison:

       -n Skips specified number of fields.  A field is defined as a string of non-space, non-tab characters separated by tabs and spaces from its
	  neighbors.

       +n Skips specified number of characters in addition to fields.  Fields are skipped before characters.

       -c Displays number of repetitions, if any, for each line.

       -d Displays only lines that were repeated.

       -u Displays only unique (nonrepeated) lines.

       If the -u flag is used, just the lines that are not repeated in the original file are output.  The -d option specifies  that  one  copy	of
       just the repeated lines is to be written.  The normal mode output is the union of the -u and -d mode outputs.

       The  -c option supersedes -u and -d and generates an output report in default style but with each line preceded by a count of the number of
       times it occurred.

See Also
       comm(1), sort(1)

																	   uniq(1)
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