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/* test.c
Experiments with syscalls
argc < 2 Print Hello World
argv[1][0] == 'p' print argv[2]
== 'e' Exec Test
== 'f' File test
== 'F' File descriptor stress test
== 'h' Halt
== '0' Null-Pointer Access
*/
#include <stdio.h>
#include <syscall.h>
#define LARGE_BUF_SIZE 4150
char large_buf[LARGE_BUF_SIZE];
#define NUM_EXEC_CHILDS 7
char *execs[NUM_EXEC_CHILDS] = { "test", "test p FOO", "test p BAR", "test f", "test 0", &large_buf[0], "test^" };
#define MAX_FD 4097
static void init_args(void);
static void init_args()
{
int i = 0;
char *t = "";
while(i < LARGE_BUF_SIZE-1) {
if(!*t) t = "test ";
large_buf[i++] = *t++;
}
large_buf[LARGE_BUF_SIZE-1]='\0';
}
int
main (int argc, char** argv)
{
if(argc < 2) {
printf("Hello World!\n");
exit(0);
}
init_args();
if(argv[1][0] == 'e') {
int r = 0;
int i;
int tid[NUM_EXEC_CHILDS];
for(i = 0; i < NUM_EXEC_CHILDS; i++) {
tid[i] = exec(execs[i]);
}
for(i = 0; i < NUM_EXEC_CHILDS; i++) {
if (tid[i] >= 0) {
r = wait(tid[i]);
printf("P child %d exited with exit code %d\n",i, r);
} else {
printf("P child %d failed to start\n", i);
}
}
} else if(argv[1][0] == 'f') {
char buf[10];
int r;
create ("test.txt", 10);
int handle = open ("test.txt");
if (handle < 2)
printf ("open(test.txt) returned %d", handle);
if ((r=write(handle,"987654321",10)) != 10) {
printf("write failed: %d not %d\n",r,10);
exit(1);
}
seek(handle,0);
if ((r=read(handle, buf, 10)) != 10) {
printf("read failed: %d not %d\n",r,10);
exit(1);
}
printf("test.txt: %s\n", buf);
} else if(argv[1][0] == 'F') {
int j,i;
create ("foo.txt", 10);
for (j = 0; j < 5; j++) {
for (i = 2; i <= MAX_FD; i++) {
if (open ("foo.txt") < 0) {
printf("Opening the %d's file failed\n",i-2);
break;
}
}
while(--i >= 2) {
close (i);
}
}
} else if(argv[1][0] == '0') {
printf("Null pointer value is: %d\n",*((int*)NULL));
} else if(argv[1][0] == 'h') {
halt();
} else if(argv[1][0] == 'p' && argc >= 3) {
printf("%s\n", argv[2]);
} else {
printf("ARGV[1] is %s\n", argv[1]);
}
return 0;
}
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