vertical 'cat' command known as a part of 'paste'

vcat.awk

#
# Usage: vcat [-v ofs=<OFS>] <file1> [file2] ...
#
# Cannot specify field of file. Use cut command instead.
#

BEGIN {
    if ( ofs ) {
        OFS = ofs
    } else {
        OFS = "\t"
    }

    max_len = 0
    for ( i = 1; i < ARGC; i++ ) {
        filename = ARGV[i]
        cnt = 1
        while ( getline line < filename ) {
            content[i,cnt] = line
            if ( cnt > max_len ) {
                max_len = cnt
            }
            cnt++
        }
    }

    for ( cnt = 1; cnt <= max_len; cnt++ ) {
        $0 = ""
        for ( i = 1; i < ARGC; i++ ) {
            $i = content[i,cnt]
        }
        print
    }
}