kernel-helloworld-test: ktestprogram/kprog.c annotate

kernel-helloworld-test

helloworld kernel module and program that reads the /dev/ktest

author	Eleni Maria Stea <eleni@mutantstargoat.com>
date	Wed, 10 May 2017 13:11:31 +0300
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rev	line source
eleni@0	1 #include <fcntl.h>
eleni@0	2 #include <stdio.h>
eleni@0	3 #include <unistd.h>
eleni@0	4
eleni@0	5 int main(void)
eleni@0	6 {
eleni@0	7 char buf[512];
eleni@0	8 size_t size;
eleni@0	9 int fd;
eleni@0	10
eleni@0	11 if((fd = open("/dev/ktest", O_RDONLY)) == -1) {
eleni@0	12 fprintf(stderr, "Failed to open device ktest.\n");
eleni@0	13 return 1;
eleni@0	14 }
eleni@0	15
eleni@0	16 if((size = read(fd, buf, sizeof buf)) == -1) {
eleni@0	17 fprintf(stderr, "Failed to read from device ktest.\n");
eleni@0	18
eleni@0	19 close(fd);
eleni@0	20 return 1;
eleni@0	21 }
eleni@0	22 printf("num char: %d\n", (int)size);
eleni@0	23
eleni@0	24 buf[size] = 0;
eleni@0	25 printf("quoting kernel: %s", buf);
eleni@0	26 close(fd);
eleni@0	27 return 0;
eleni@0	28 }