How can I get the length of a data vector?

[ljdeng]

I am a new user of opensees and tcl language.
I am wondering how I can automatically get the length of a data vector, for example, an earthquake time history; therefore I can know how many steps to "analyze". Similar commands like last(file) in Matlab and rows(file) in MathCAD?
Many thanks.

[silvia]

you have to load up the file into a list and then use: llength command.
www.tcl.tk/man/tcl8.5/TclCmd/contents.htm

[ljdeng]

Thanks Silvia. I made a proc to load the file into a list, and it works well.

proc EventLength filename {
set file [open $filename];
set iDstep [read $file];
set eventlist [list 0];
foreach Dstep $iDstep {
lappend eventlist $Dstep; };
set eventNo [llength $eventlist];
return [expr $eventNo-1];
}