Final (Unix 2)

Question 1

What are process priorities?

Answer 1

Relative importance or priority assigned to processes by the operating system’s scheduler. The scheduler is responsible for determining which processes get CPU time and in what order.

Question 2

What is a shell script?

Answer 2

A file which contains a set of predefined shell commands and/or operations written in a scripting language (such as Bash) which is interpreted by the shell.

Question 3

What is egrep?

Answer 3

Extended grep. It allows (), +, -, ?, |, and other operators that normally don’t work with grep.

grep -E option can also generally produce this behavior.

Question 4

What do the -i, -w, -c, -v, -l, and -E options do in a grep command?

Answer 4

-i: ignores case
-c: causes the number of lines matched to be printed
-w: forces search to look for entire words
-v: causes lines that -don’t- match to be output
-l will return only the name of the file(s) if grep finds a match
-E allows use of (), +, -, I, ? and other operators that normally don’t work with grep

Question 5

What is the syntax of grep?

Answer 5

grep <options> <pattern> <files></files></pattern></options>

Question 6

What would the command:

grep crap MyFile.txt

do?

Answer 6

Search the file MyFile.txt for any instance of the character sequence crap in the text and return them.

Question 7

What would the command:

grep ^This MyFile.txt

do?

Answer 7

Look for line starting with “This” in MyFile.txt

Question 8

What would the command:

grep receive *.sh

do?

Answer 8

Look for “receive” in any file ending in .sh

Question 9

What would the command:

grep “[abc].*” MyFile.txt

do?

Answer 9

Find a substring with an a, b, or c, followed by any number of other characters.

Question 10

What would the command:

grep “ii*” MyFile.txt

do?

Answer 10

It would check MyFile.txt for any line that has one or more i characters in it, including multiple i characters in a row.