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# 1  
Old 09-25-2008
field replacement
Hi,

I have a CSV file with around 1000 rows (lines) and 1000 columns (fields).
I need to replace mth lines's nth field with a value. (E.g., 400th field of 300th line). how can i do that?

Pl advise.

Thanks
Prvn
# 2  
Old 09-25-2008
what have you tried?
# 3  
Old 09-25-2008
I tried extracting the fields other than to be replaced. Using "echo" i could again write to another file with new value.

It worked but looked very inefficient. i guess it can be easily achieved with "awk". Pl advise.


Prvn
# 4  
Old 09-25-2008
show your code.
# 5  
Old 09-25-2008
get the input from the user like lineno and columnno the rest is done by this awk
Code:
 
awk -F"," -v var1=$lineno -v var2=$columnno 'NR == var1{gsub(var2,"value")}{print $0}' filename

# 6  
Old 09-25-2008
Actually you could simply do

Code:
awk -F, -v line=$m -v col=$n 'NR == line { $col="value" }1' filename

# 7  
Old 09-25-2008
Thanks Vidhyadhar and era.

Era - when i used your solution, replacement done but "," also vanished.

#cat /tmp/test
1,2,3
4,5,6
7,8,9
#gawk -F, -v line="2" -v col="2" 'NR == line { $col="value" }1' /tmp/test
1,2,3
4 value 6
7,8,9
#

Vidhyadhar - when i ran your solution, o/p remains as acutal file contents (no replacements done).


Thanks
Prvn
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