Error messages generated by commands are sent where by default?
Log files
STDOUT
STDERR
STDIN
A successful command will print output to STDOUT.
Which of the following commands will direct error messages to the file, error.log?
ls /root >> error.log
ls /root 2> error.log
ls /root $> error.log
ls /root > error.log
A pipe allows you to…
…send the same input to multiple commands.
…type multiple commands at one prompt.
…send the output of one command to another.
…send the output of a command to a file.
Channel 2 is:
STDALL
Which of the following commands will append its output to output.file?
echo Testing > output.file
echo Testing >> output.file
output.file < echo Testing
echo Testing -> output.file
Which command(s) can be used to sort the lines of list.file alphabetically and display it on the screen?
sort < list.file
cat list.file | sort
cat list.file >> sort
echo list.file > sort
Which option of the head command will display only the first five lines of a file?
-l 5
No option needed; head displays only five lines by default.
-n
-n 5
The grep command…
…will display all the lines that begin with the specified Regular Expression.
…is not case sensitive.
…will display all the lines in a file containing the specified Regular Expression.
…will display the line numbers in a file that contain a specified Regular Expression.
The grep command can be used with glob characters.
Which of the following commands will display only lines that begin with start?
grep *start file.txt
grep $start file.txt
grep start file.txt
grep ^start file.txt
Which of the following commands will display only lines that begin with test?
grep ^test file.txt
grep $test* file.txt
grep *test file.txt
grep &test file.txt
Which of the following commands will display lines that contain either start or end?
egrep start end file.txt
egrep ‘start|end’ file.txt
egrep start&end file.txt
egrep (start|end) file.txt
Which of the following commands can be used to scroll through a text file?
some
less
cat
more
The find command can search for files based on the size of the file.
Which of the following commands scans the file to determine file locations?
search
locate
where
find
Which option for the cut command is used to specify a delimiter?
-f
-d
=
-D
Which option for the cut command is used to specify the field?
#
Which option for the wc command will print the number of lines in a file?
-l
-w
-C
-L
Which option for the wc command will print the total number of words in a file?
Which command can be used to print line numbers?
num
sort
ln
nl
The command echo “text” > file.txt will create file.txt if it does not already exist.
The command echo “text” > file.txt will not overwrite file.txt if it already exists.
The command echo “text” >> file.txt will not overwrite file.txt if it already exists.