Write a C program in Linux that will read from an input ﬁle a sequence of student records, will
sort them, and will print the sorted records into an output ﬁle. The input ﬁle will be a text ﬁle
containing information about one student per line. Each line will include the following information
in the following format:
StudentID Firstname Lastname Department GPA
You can assume each of the above information (Firstname, Department, etc.) will be a single
word. Assume StudentID is a 7 digit number between (and including) 1000000 and 9999999. Assume
GPA is a ﬂoating point number between (and including) 0 and 4. There can be one or more space or
TAB characters between the ﬁelds. If you use the fscanf() function, then this will not matter and
you will be able to read the ﬁelds of a line easily into your variables. Note that Firstname, Lastname,
and Department can be any length, therefore make sure you do not make any assumption about their
lengths and create the memory required to hold them dynamically (Tip: the m modiﬁer of fscanf()
might be handy here).
Your program will read the information from the input ﬁle and will build a linked list where each
item (entry) of the list will contain information about one student. Hence each item of the linked list
will be a structure having ﬁelds to store information about a student (in C we do not have class, we
have struct). You can build the list as a doubly linked list. In this case, each item in the list will
have also a pointer to the next item and a pointer to the previous item.
After building the list, your program will sort the list using the insertion sort algorithm (Tip: You
can build the list in the sorted order as well.). Sorting will be done based on the StudentID ﬁeld.
Then your program will write the list of items into an output text ﬁle. Each line of the output ﬁle will
contain information about one student in the following format:
Note the comma (instead of space or TAB characters) between ﬁelds. The output should contain
no spaces or TABs, and no empty lines. So, after you write the last line of information, you should
close the ﬁle. And this should be the end of your program. It is very important that you produce the
output in this format since we will use this format in our automated tests.
It is a requirement that you have to use linked list data structure and insertion sort algorithm. In this
way, you will be able to practice with pointers and structures.
The name of your executable ﬁle has to be unisort. A sample invocation of your program can
be like the following:
unisort in.txt out.txt
Here, in.txt is the input text ﬁle, and out.txt is the output text ﬁle. It is very important that
you follow the speciﬁcations.
Example 1 An example input ﬁle (for example, in.txt) can be like the following:
2040003 AAAA BBBBBBBBB ComputerScience 3.45
2040002 AAA CCC ElectricalEngineering 3.01
2040005 AAAAAAAAAAAAAAAAA BBB ComputerScience 3.60
Then the output ﬁle (for example, out.txt) will be the following: