UNIX for Dummies Questions & Answers

123
1234|123|123|123
123|123|456
123|123|12
12

123
1234|123
123|123
123|123
456
123|123
12
12

123|123|123|123|123

123|123
123|123
123

awk -F \| '
    NF %2 {
        for( i = 1; i < NF-1; i += 2 )
            printf( "%s|%s\n", $(i), $(i+1) );
        printf( "%s\n", $(i) );
        next;
    }

    {
        for( i = 1; i < NF; i += 2 )
            printf( "%s|%s\n", $(i), $(i+1) );

    }
' input-file

awk -F \| '
    {
        for( i = 1; i < NF - (NF%2); i += 2 )
            printf( "%s|%s\n", $(i), $(i+1) );
        if( NF % 2 )
            printf( "%s\n", $(i) );
    }
' input-file