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Full Discussion: String pattern matching and position
Top Forums UNIX for Dummies Questions & Answers String pattern matching and position Post 302915033 by Don Cragun on Saturday 30th of August 2014 05:47:16 PM
Old 08-30-2014
The awk utility is also only defined to work when the input files it reads are text files. So, although some versions of awk can handle long, and/or incomplete lines or both, many cannot. If you would like something that should work on any UNIX or Linux system, you could try something like this:
Code:
awk '
function p(spot) {
	printf("%10d %10d\n", ++cnt, spot)
}
te && /^[Rr]/ {
	p(te)
}
{	while(match($0, /[Tt][Rr]/)) {
		p(off + RSTART)
		$0 = substr($0, 1, RSTART - 1) " " substr($0, RSTART + 1)
	}
}
{	off += length($0)
	if($0 ~ /[Tt]$/) {
		te = off
	} else	te = 0
}' input.txt

Note that this works on your input file before stripping out the <newline> characters, so instead of having to allocate 200Mb of memory to read in your one-line file, it just needs to read one ~50 character line at a time.

With the following randomly generated list of upper- and lower-case letters (except for the 1st 8 and last 8 characters in the file):
Code:
TrTRtrtRmzGArXRqWdKOmxzDWLKZVnPRRrAVNcpAflTxvLkLbs
NbZdBuopHQnEqVJiLWYHVZUfHLqUTmRPesoqVbVdgXXglCCEQC
ZRfvLdXyfgpufseFnIIboRbtDXtlttNQudyeOGyLvLGzSOPyMo
VpxGVwNJKXpYUlhZuNgIcgYuscJRzmExrJZWeeRgnHXwxkxbKh
mndPLikztEWtlovWaOddGCSEijRtrkgWWzvQADIQhsfVEAwmXQ
eIImjmJnvLTQLubbchEwLclnjVmUKuIRxmUOSmarnWYyEBKQpX
gEpdrIXIXiUsiMjQQWWIYWYCfSBwMsPQwvLHyGRwKldfvOxzar
xgwKodWiJxgAhVhlCfalWRpijwiHRlYntBOxweZrvwPPLTYpmN
REPdLIcZnBLWORUkpLCBtlTzjOmQBDVuFEAYfzLTIbyZaNVUMt
rfDzbKDxzXoCqnpWntyTrkyIrSrZTopjapZFouHDGxmlZmxswW
AcvPaJKxLSXZLCLfRZVuxusjYcKzlpZajBMvweadarCAIGjPdM
yiFAqrMDySoxpPREnFPHDQaFJDVUDsYXmbZGkhbvImOkCKfAsg
kauwlSzzrbqrBrXCLJsHXlHAdoRBjXjQbUoFJslyENNKnjIADT
RMEZvOSLWqHeeEoIUddxBxdHuuEMqTpYVTIoGUNVPxKPcSadji
ecsIoISmpwIPIqCXYdwqsvbtTKuoQflREDkZPLxtlyfOVeuKxj
LkwARhocaWFEMjZlPHtuCiYmxfqtYSGwlRSLZHzYGDZoHzvJbm
GsXLsRcuvLEQcXPRakbdeHGLrrnZgwyMFHmXNMmNNbEnfkXumM
pUSpOhpTakWOpQNohhjcuObfSfteNBMyJivKQKhPJQtrtRTrTR

it produces the output:
Code:
         1          1
         2          3
         3          5
         4          7
         5        228
         6        450
         7        470
         8        650
         9        893
        10        895
        11        897
        12        899

giving you the number of matches found and their positions in the file (not counting <newline> characters).
This User Gave Thanks to Don Cragun For This Post:
Scrutinizer
 

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