Implementation of library management system with C language

So far, I have studied C language with the progress of the school for about half a year. I only learned the pointer in basic learning and learned it very shallow. To tell the truth, the initial impression of C language is just a stepping stone to learn computer language. I'm very confused about how to apply C language. It was not until I tried the complete small program of graphical interface run by DOS after the high-level language design course in the first half of my freshman year that I found the charm of C language.

OK, no more nonsense. Here is my work in the second class - the library management system in C language. A simple applet. It is not purely original, but adapted from the "student management system" found on the Internet. By directly browsing and modifying a complete code, I have gained a lot. I think this is more efficient, easy to understand and easy to remember than boring learning code. Here are some useful points I learned when modifying the program:

(these may be very simple, but I really haven't learned (⊙ n ⊙ b) before)

1. Color setting of DOS interface (background, font color)

color [attr]

The following is the color code: (for example, color FC is bright white to produce bright red, the first background and the second foreground)

0 = black 8 = gray 1 = Blue 9 = light blue 2 = green a = light green 3 = lake blue B = light green 4 = Red C = light red 5 = purple d = light purple 6 = yellow e = light yellow 7 = white f = bright white DOS can only display these basic colors and cannot customize other colors by yourself

2. String comparison (for password verification, etc.)

StrCmp is a function prototype for comparing strings: extern int StrCmp (char * S1, char * S2); Usage: #include < string h> Function: compare strings S1 and S2. Note: when S1 < S2, the return value is < 0. When S1 = S2, the return value is = 0. When S1 > S2, the return value is > 0

3. File operation in C language

Define a symbol representing a file (pointer variable) in the form of file * FP

The statement to open the file is

Fopen (file location, open mode);

The file location is easy to understand. It is the location of the file, such as D: / / test txt

There are several open modes,

R (read): read

W (write): write

A (append): append

T (text): text file, which can be omitted without writing

B (binary): binary file

+: read and write

Generally RT + can also be written as R + and W +, that is, reading and writing can retain the original content. So open the file C: \ my \ test. In my directory on drive C Txt statement is

FP = fopen ("C: / / my / test. TXT", "R +"). Note that the folder symbols are different from those above.

4. Code module (verify password, query information, modify information, delete information)

① Security verification

② Query book information

The principle is that the student numbers in all stu arrays are stu [i] through a loop Num is compared with the student number num to be queried. If it is the same, it will be displayed in printf.

③ Modify book information

The function is change (students stu [])

The principle is to locate first, and then enter a new value to replace the previous value.

④ Delete book information

The function is void delete (students stu [])

The main principle is

If a match is found, the next name overwrites the previous one

The following is the complete main program code:

For more learning materials, please pay attention to the special topic "management system development".