IMPLEMENTATION OF I/O SYSTEM CALLS

[open(),read(),write()]

AIM:

To write a c program to perform operations on files using LINUX system calls open(),read(),write()

ALGORITHM:

Step1: Start the process.

Step2: Declare and initialize an array variable.

Step3: Declare a file pointer.

Step4: Using the open() system call, open a file in a write mode and store it in a file

Pointer.

Step5: Using the write()system call, write the contents of an array to the file.

Step6: The written file is read with the help of read() system call. Then Close the file.

Step7: Stop the process.

PROGRAM:

#include<stdio.h>

#include<stdlib.h>

double d[10]={1.3,1.0,1.23,1.9,0.91,1.5,1.4,0.0,1.01,8.15};

int main( void)

{

int I;

FILE *fp1;

if((fp=fopen(“my.txt”,”wb”))==NULL)

{

printf(“Cannot open file \n”);

exit(1);

}

/* write the entire array in one step */

if(fwrite(d,sizeof(d),1,fp)!=1)

{

printf(“write error \n”);

exit(1);

}

fclose(fp);

if((fp=fopen(“my.txt”,”rb”))==NULL)

{

printf(“Cannot open file \n”);

exit(1);

}

/*clear the array */

for(i=0;i<10;i++)

d[i]=0.0;

/* read the entire array in one step */

if(fread(d,sizeof(d),1,fp)!=1)

{

printf(“read error \n”);

exit(1);

}

fclose(fp);

/*display the array */

for(i=0;i<10;i++)

printf(“%f”,d[i]);

return 0;

}

OUTPUT:

1.300001.1.000001.230001.90000000.9100001.5000001.40000000.000001.0100008.150000

RESULT:

Thus the given C Program is executed and output is verified.