Shell Programming and Scripting

#!/usr/bin/env sh

# @(#) a1       Demonstrate embedded field separator correction.

set -o nounset
echo

## Use local command version for the commands in this demonstration.

echo "(Versions used in this script displayed with local utility "version")"
version bash awk

echo

# Create data file.

cat >data1 <<'EOF'
now|is|the|time
for|all|go|od|men
to|come|to|the
aid|of|their|country
EOF

# This assumes that if an embedded separator appears, it will be
# in field 3, and so the separator number 3 will be replaced with
# the null string.  This is essentially a trial-and-error
# solution.

echo " Data file:"
cat data1

echo
echo " Results of correction:"
awk '
BEGIN   { FS = "|" }
NR == 1 { f = NF }
        {
                if ( NF != f ) {
                        print " BANG! found discrepancy at line", NR # remove as desired
                        $0 = gensub("[|]","",3,$0)
                }
                print $0
        }
' data1

exit 0

% ./a1

(Versions used in this script displayed with local utility version)
GNU bash, version 2.05b.0(1)-release (i386-pc-linux-gnu)
GNU Awk 3.1.4

 Data file:
now|is|the|time
for|all|go|od|men
to|come|to|the
aid|of|their|country

 Results of correction:
now|is|the|time
 BANG! found discrepancy at line 2
for|all|good|men
to|come|to|the
aid|of|their|country