why I cannot use airport command in terminal?

if you are going to use an alias, you need to use the full path to the executable - as mentioned earlier, there was an extra space that shouldn't have been there, so it would be:

alias airport="/System/Library/PrivateFrameworks/Apple80211.framework/Versions/A/Resources/airport"

Hello,

The command-line tool airport isn't in one of the normal locations that are searched for use in the command line. You will have to provide the full path:

/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resource s/airport

First you will probably have to fix the extra space that the forum software seems to have inserted. There are no spaces in that that. You can just type the whole thing. If you want, you could add something like this in .bash_profile:

alias airport="/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resource s/airport"

Sorry, when I go to edit the above, there is no space. I can't fix it. There shouldn't be a space there.

That path is to the executable itself, so you would either need to just add the containing folder to your PATH, use the alias, or use the entire path:

/System/Library/PrivateFrameworks/Apple80211.framework/Versions/A/Resources/airport -h

When that full path works but your shortcuts don't, that indicates that the issue is either with the PATH or alias in your profile. Whichever one you are using, check that the alias is set to the full path to the executable (without that extra space), or that your PATH variable includes just the containing folder (without that extra space):

/System/Library/PrivateFrameworks/Apple80211.framework/Versions/A/Resources

Don't use just airport -h - does copying and pasting the entire command work?

/System/Library/PrivateFrameworks/Apple80211.framework/Versions/A/Resources/airport -h

Copying that command (the -h option just shows the help) into the Terminal doesn't work? Can you navigate that path and find the airport executable?