ls -l /home/ghoffman/html/it244_html
lsto see the directory contents in reverse order by date
ls -ltr /home/ghoffman/html/it244_htmlHere you are combining the options indicating you want a long listing (l), ordered by date and time (t), in reverse order (r).
lsto see the access permissions on the it244_html directory
ls -ld /home/ghoffman/html/it244_htmlHere you are combining the options indicating you want a long listing (l) of the directory itself (d), not its contents.
dfto see the disk space available on users3.cs.umb.edu
dfNotice two things.
dfwith the -h option
df -hThe free disk space is now much easier to read.
ls --helpNotice that some help is very long.
cddoes not respond to the --help option, or, for that matter, -h.
lsusing only the name of the command
lsusing an absolute pathname
/bin/ls ~ghoffmanThis has the same effect as typing the name of the command on the command line, which is also the name of the executable file for
echo $PATHNotice that each directory name is an absolute pathname separated by a colon, :.
cp ~ghoffman/course_files/it244_files/hello.sh .
hello.shYou get an error message.
./hello.shNow the program runs.
lswith no options or arguments
lsran without any problems, it returned an exit status of 0, indicating that all went well.
lson a file that doesn't exist
lsfailed, it returns a non-zero exit status.
ls --help | tailReturning the value 2 means
lsran into a serious problem.
~ghoffman/it244_test/ex11.shWhen the script asks if you are ready for more, hit Return or Enter.