I didn't see any hits about this on google, so I'm asking you:I just tried to run this command in an ssh session, local is Debian Wheezy KDE, remote is Fedora 21 Gnome:ps aux |grep xscreensaverand this is the output:bash: grep: command not found...I never seen this before, what is the cause?I just few hours before updated the system, but didn't see any packages marked for removal. There are only two users on the system, and only me installs or removes software on it.EDIT #1Here is the commands and output copied,notice that the space is not there the second time:[root@Hostname ~]# ps aux | grep xscreensaverbash: : command not found...[root@Hostname ~]# ps aux |grep xscreensaverbash: grep: command not found...
Why is this command not working: ps aux | grep xscreensaver
bash;grep;command not found
Note the double space in bash's error message before grep: that probably means you've typed an unbreakable space (AltGr+space), which can happen quite easily if your keyboard requires AltGr to produce the pipe symbol.Try dropping the spaces around the pipe symbol:ps aux|grep xscreensaverIn your updated examples:[root@Hostname ~]# ps aux |  grep xscreensaverbash:  : command not found...bash is trying to run the unbreakable space command, which doesn't exist; hence the error message, unbreakable space: command not found...[root@Hostname ~]# ps aux | grep xscreensaverbash:  grep: command not found...bash is trying to run the command whose name is grep preceded by an unbreakable space, which doesn't exist either; hence the error message with two apparent spaces between bash: and grep.