how to display the input in a desired format

input file contains some contents such as :

15-05-2011  16:05    <DIR>          .
15-05-2011  16:05    <DIR>          ..
24-04-2011  16:07    <DIR>          Administrator
15-05-2011  16:05    <DIR>          confuser
01-02-2011  20:57    <DIR>          Public
29-01-2011  19:28    <DIR>          TechM
12-08-2011  09:36    <DIR>          vt0013487

I need to give the file name in the command line argument

the output to be in the desired format:

Administrator 24-04-2011  16:07 
confuser      15-05-2011  16:05 
Public        01-02-2011  20:57 
TechM         29-01-2011  19:28 
vt0013487     12-08-2011  0开发者_Go百科9:36

So you're doing some fixed-width-field input parsing except that the final field is variable length and extends to the end of the line. That's easy enough. The only awkward bit is that we need to read in all the lines to get the width for the first field of the output format.

Assuming you supply the input on stdin (i.e., by redirection) and want it on stdout (so you can also redirect that to a file):

##### Read in and compute the width
set len 0
while {[gets stdin line] >= 0} {
    set date [string range $line 0 16]
    set name [string range $line 36 end]
    lappend lines $name $date
    if {[string length $name] > $len} {
        set len [string length $name]
    }
}
##### Write out as formatted
foreach {name date} $lines {
    puts [format "%-*s %s" $len $name $date]
}

split to break the input into lines, foreach to iterate over them, regexp to extract relevant groups of characters from those lines, format to construct resulting strings (format is often not needed in Tcl as simple variable substitution in strings usually works just okay for common cases).

Read this, this, this and this. Also this for the syntax used by the regexp matching engine.

Also I suspect you may be trying to use the output generated by exec'ing the DOS dir command instead of using glob to traverse directories and files natively. If so, this is wrong, use glob

This may not answer your question: If you are calling cmd /c dir, here's a way to do it in Tcl:

package require struct::list
set files [glob *]
set maxlen [tcl::mathfunc::max {*}[struct::list map $files {apply {s {string length $s}}}]]
foreach file [lsort $files] {
    set datetime [clock format [file mtime $file] -format {%d-%m-%Y %H:%M}]
    puts [format {%-*s %s} $maxlen $file $datetime]
}