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Old 04-17-2008, 03:28 AM   #1
lawrence_lee_lee
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How to use "awk" to do the following seemingly simple work?


1) Given an input file, I want to perform some action to a line subject to some conditions of the next line. For example,

if the next line is "======" then I want to print the current line.
How can such actions be performed using awk?

2) Is there any method for awk to go back one/more line(s) when reading a file?

3) What is the difference between these two intrinsic variables: NR and FNR?

4) Does awk support multidimensional array?
 
Old 04-17-2008, 04:29 AM   #2
Tinkster
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Quote:
Originally Posted by lawrence_lee_lee View Post
2) Is there any method for awk to go back one/more line(s) when reading a file?
No.

Quote:
Originally Posted by lawrence_lee_lee View Post
1) Given an input file, I want to perform some action to a line subject to some conditions of the next line. For example,

if the next line is "======" then I want to print the current line.
How can such actions be performed using awk?
Store each line in a transient buffer, compare to current and
print it.

Quote:
Originally Posted by lawrence_lee_lee View Post
3) What is the difference between these two intrinsic variables: NR and FNR?
NR is the TOTAL number of records seen, FNR pertains
to the "current file".

Quote:
Originally Posted by lawrence_lee_lee View Post
4) Does awk support multidimensional array?
Yes.



Cheers,
Tink
 
  


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