Experiments on GNU/Linux

#To get emails from CSV which is exported form your mail box
 
grep -o -i '[^,]*@[^,]*' contacts.csv 
 
#Cut the required column assuming delimiter to be ","
 
cut -d, -f2,3 < input.csv 
 
#For given index range 
 
grep ${VALUE} input.csv | cut -d, -f${INDEX}
 
#Get first two columns of the cvs file
 
awk '{print $1"\t"$2}' input.csv
 
#CSV which is of the regex /^(.*),,/ $f is the file here
awk -F,'{ if ($1 != "") prefix=$1; else printf "%s%s\n", prefix,$0 }' $f
 
# CSV of the format  field1 , field2  , field3  , field4
# we can set the FS to a regexp as FS=’^ *| *, *| 
 
# FS=','
for(i=1;i<=NF;i++){
  gsub(/^ *| *$/,"",$i);
  print "Field " i " is " $i;
}
 
 
# For CSV of the format "field1","field2","field3","field4"
# we can set the FS to FS=’^”|”,”|”$’ or FS=’”,”|”‘
 
# FS=','
for(i=1;i<=NF;i++){
  gsub(/^ *"|" *$/,"",$i);
  print "Field " i " is " $i;
}
 
 
#For CSV => field1,"field2,with,commas",field3 ,"field4,foo"
 
$0=$0",";                                  
while($0) {
  match($0,/[^,]*,| *"[^"]*" *,/);
  sf=f=substr($0,RSTART,RLENGTH);          # save
  gsub(/^ *"?|"? *,$/,"",f);               # remove extra
  print "Field" ++c " is " f;
  sub(sf,"");                              # that which is matched
}
 
 
 
This is my personal collection.
Most of them suggested by the uber cool g33ks of terminal.
Few bits patched by me.Out there are many ways 
please do comment them here.