some bash commands dosen't work
 

I'm using Red hat valhall 7.3 and i found a page with linux bash commands but i cant use some
input: fdisk
output: Bash: fdisk: command not found


i.e Fdisk,unmount,cron and more

You have to be logged in as root-user to use the fdisk -command.
There is not any "unmount" -command, the name uf the caommand us "umount"

Also, please be aware for umount/mount you CANNOT be in the same directory. If you are in /mnt/floppy when you're trying to unmount your floppy, it won't work.

I didn't know about that one Squall. Not that I'm ever in that situation, but it's a useful thing to know.

bear in mind that there's root access only commands that won't work even if you "su" to change to root as certain paths are not accessible (without the full path to the command) if you don't su and make that the login shell -> use the "su -" command to load /sbin/ and /usr/sbin in the path. using "su -" will let you just use "fdisk" to start up fdisk. the full path to fdisk is /sbin/fdisk in rh 7.3.