How do I join two files vertically without any separator? I tried to use paste -d a b, but this just gives me a.Sample file:000    0   0   00001000200030004  10  20  30  40    2000    4000            .123            12.11234234534564567
paste files without delimiter
text processing;files;paste
paste use \0 for null delimiter as defined by POSIX:paste -d'\0' file1 file2Using -d a b is the same as -d a b: the paste program sees three arguments -d, a and b, which makes a the delimiter and b the name of the sole file to paste.If you're on a GNU system (non-embedded Linux, Cygwin, ), you can use:paste -d  file1 file2The form -d  is unspecified by POSIX and can produce errors in other platforms. At least BSD and heirloom paste will report no delimiters error.