Comments on: file read-write operation…unexpected output… plz explain… https://www.emblogic.com/blog/08/file-read-write-operation-unexpected-output-plz-explain/ Embedded System and ARM Training Mon, 07 Oct 2013 04:00:03 +0000 hourly 1 http://wordpress.org/?v=3.9.1 By: rahul1989 https://www.emblogic.com/blog/08/file-read-write-operation-unexpected-output-plz-explain/#comment-1384 Sun, 19 Aug 2012 02:46:40 +0000 http://emblogic.org/blog/?p=4873#comment-1384 char ch = 144
giving negative integer value because overflow had started

]]> By: rahul1989 https://www.emblogic.com/blog/08/file-read-write-operation-unexpected-output-plz-explain/#comment-1383 Sun, 19 Aug 2012 02:45:17 +0000 http://emblogic.org/blog/?p=4873#comment-1383 look your code carefully.
you have done big mistakes.
ch=144
in this line you are trying to enter the multiple character in a single character.
char is 1 byte data type.
to print desired result you need to take 144 as a string.
one another method that if you take ch as int type instead of char then your problem may resolve.
i am giving you 1 e.g..

void main()
{
int ch=144;
int str;
int fd;
fd=open(“transfer.txt”,O_WRONLY|O_CREAT|O_TRUNC);
if(fd<0)
{
perror("fault\n");
exit(1);
}
write(fd,&ch,sizeof(int));
close(fd);
fd=open("transfer.txt",O_RDONLY);
read(fd,&str,sizeof(int));
printf("%d\n",str);
close(fd);
}

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