mkdir

make a directory ; optionally the necessary hierarchy with -P or --parent

mkdir [-m u=rws,g=rx,o=rx | --mode=mmm]
          [-p |--parents] [-v | --verbose] [-Z] dir[/dir[…]]

--mode set file mode (as in chmod), not a=rwx - umask.
-p
--parents 		Crerate intermediate directories as needed with mode="rwxrwxrwx" (0777) as modified by the current umask. 
$ mkdir -p animal/warmblooded/horse
--verbose
-v		Verbose, especioally seful with --parents/.
-Z set SELinux security context of each
Examples: As a script: 
 if [ -e  $1 ]; then  ls -ld $1 ; exit 1; fi # dont bother telling him, just show it
if [ -e $1 ]; then echo \-\- $1 exists as a file     ; ls -l $1;exit 2 ;fi
mkdir  $1
if [ $? -ne 0 ]; then echo " - stink! didn\'t work" ;  ls -ld newdir ; exit 2 ; fi
ls -ld newdir 
# need option to stay in newely created directory which is ??
cd newdir