Linux Internship Report - Experiment 3 C Development Tools

Purpose

1. Learn to use gcc, make, gdb tools
2. familiar with c language

content

1. Write a C language program: output two lines of text "C under Linux is not too difficult!". Edit, compile, and run the program under Linux.

Step 1: Start the vim editor and write code in it;

#include<stdio.h>
int main(){
printf("Linux下的c也不是太难嘛！\n");
return 0;
}

Step 2: Compile the program gcc text.c -o text;

Step 3: Run the program ./text to get the result.

 2. Write a c language program: average two integers input and output at the terminal, and generate its assembler file through the gcc compiler.

Step 1: Start the vim editor and write code in it;

#include<stdio.h>
int main(){
    float avg;
    int a,b;
    scanf("%d %d",&a,&b);
    avg=(a+b)/2.0;
    printf("%f",avg);
    return 0;
}

Step 2: Compile the program gcc -o avg avg.c;

Step 3: Run the program ./avg to get the result.

 3. Use the gdb debugger to debug the program in question 2 above, check the value of the variables in each step of the program execution, and be familiar with the use process of gdb.

4. Build a simple program and practice the creation method of function library. The function library contains two functions and is called in a sample program (prom.c), these two functions are fast.c (quick sort), insert.c (insertion sort), which implements ascending sorting of one-dimensional arrays . Follow the steps below to generate the function library.

1) Write prom.c, fast.c, insert.c respectively;

Start the vim editor to write the fast.c program;

#include<stdio.h>
int fast(int a[],int n){
     int t;
     for(int i=1;i<10;i++)
        for(int j=i+1;j<11;j++)
           if(a[i]>a[j])
              { t=a[i];
                a[i]=a[j];
                a[j]=t;
              }
     return 0;
}

Start the vim editor and write the insert.c program code;

#include<stdio.h>
int insert(int a[],int n){
    int i,j;
    for(i=2;i<=n;i++){
       a[0]=a[i];
       j=i-1;
      while(a[0]<a[j]){
         a[j+1]=a[j];
         j--;
      }
     a[j+1]=a[0];
    }
    return 0;
}

Start the vim editor and write the prom.c program;

int main()
{
    int a[11],i;
    for (i=1;i<=10;i++)
scanf("%d",&a[i]);
fast(a,10);
    insert(a,10);
    printf("插入数据排序后顺序：\n");
    for(i=1;i<11;i++)
        printf("%2d",a[i]);
    printf("\n");
    return 0;
}     

2) Compile these two programs to generate target files fast.o and insert.o

gcc -c fast.c insert. 

 According to the prompt, the code must be compiled under std=c99.

3) Create the library file libfoo.a

ar crv libsort.a fast.o insert.o

4) Compile prom.c without library

gcc -c prom.c

gcc prom.o fast.o  insert.o -o prom1

5) Compile prom.c with the library file libsort.a

gcc -o prom2 prom.o libsort.a

6) Use the library file lib sort .a to compile prom.c, use the l option to access the function library, and use the L option to indicate the directory where the library file is located

gcc -o prom3 prom.o -L. -lsort

7) Try to write a Makefile rule file to manage the project file, and use make to compile it as prom4;