Someone

# ls -lR / > /tmp/allfiles.txt
ls: /proc/2/exe: No such file or directory
ls: /proc/3/exe: No such file or directory
ls: /proc/3162/fd/3: No such file or directory
ls: /proc/4/exe: No such file or directory
ls: /proc/5/exe: No such file or directory
ls: /proc/6/exe: No such file or directory
# grep -i tftp /tmp/allfiles.txt
/bin/sh: grep: not found
#