UNIX for Dummies Questions & Answers

#!/usr/bin/env bash

# @(#) s1       Demonstrate sifting, collecting lines to files, awk.

# Utility functions: print-as-echo, print-line-with-visual-space, debug.
# export PATH="/usr/local/bin:/usr/bin:/bin"
LC_ALL=C ; LANG=C ; export LC_ALL LANG
pe() { for _i;do printf "%s" "$_i";done; printf "\n"; }
pl() { pe;pe "-----" ;pe "$*"; }
db() { ( printf " db, ";for _i;do printf "%s" "$_i";done;printf "\n" ) >&2 ; }
db() { : ; }
C=$HOME/bin/context && [ -f $C ] && $C awk

FILE=${1-data1}

# Remove debris.
rm -f [0-9]*.txt

pl " Input data file $FILE:"
cat $FILE

pl " Results:"
awk '
BEGIN          { outfile = lastfile = "" }
NR == 1        { lastfile = $3; outfile = $3".txt" ; print > outfile ; next }
$3 == lastfile { print > outfile; next }
               { close (outfile) ; lastfile = $3 ; outfile = $3".txt" ; print > outfile }
' $FILE
wc -l [0-9]*.txt

sample=109.txt
pl " Sample output: file $sample:"
cat $sample

exit 0

$ ./s1

Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: SunOS, 5.10, i86pc
Distribution        : Solaris 10 10/08 s10x_u6wos_07b X86
bash GNU bash 3.00.16
awk - ( local: /usr/xpg4/bin/awk, Oct 10 2007 )

-----
 Input data file data1:
1       1111111111111   108
1       1111111111111   109
1       1111111111111   109
1       1111111111111   110
1       1111111111111   111
1       1111111111111   111
1       1111111111111   111
1       1111111111111   112
1       1111111111111   112
1       1111111111111   112

-----
 Results:
       1 108.txt
       2 109.txt
       1 110.txt
       3 111.txt
       3 112.txt
      10 total

-----
 Sample output: file 109.txt:
1       1111111111111   109
1       1111111111111   109