Unable to display everything in C using fprintf and fflush - c

I am having trouble understanding why I can see some output but cannot see the output for certain other lines of the code below. I am using PAPI and C.
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <memory.h>
#include <malloc.h>
#include "papi.h"
#define INDEX 100
static void test_fail(char *file, int line, char *call, int retval);
int main(int argc, char **argv) {
extern void dummy(void *);
float matrixa[INDEX][INDEX], matrixb[INDEX][INDEX], mresult[INDEX] [INDEX];
float real_time, proc_time, mflops;
long long flpins;
int retval, status = 0;
int i,j,k;
long_long values[1];
FILE *file;
file = fopen("output.txt","w");
retval = PAPI_library_init(PAPI_VER_CURRENT);
int EventSet = PAPI_NULL;
PAPI_create_eventset(&EventSet);
if(PAPI_add_event(EventSet, PAPI_L1_DCM) != PAPI_OK)
{
fprintf(file,"PAPI failed to add Load/Store instructions\n");
}
if (PAPI_state(EventSet, &status) != PAPI_OK)
fprintf(file,"PAPI fail\n");
fprintf(file, "State is now %d\n", status);
if (PAPI_start(EventSet) != PAPI_OK)
fprintf(file,"PAPI fail\n");
if (PAPI_state(EventSet, &status) != PAPI_OK)
fprintf(file,"PAPI fail\n");
fprintf(file, "State is now %d\n", status);
/* Initialize the Matrix arrays */
for ( i=0; i<INDEX; i++ ){
mresult[0][i] = 0.0;
matrixa[0][i] = matrixb[0][i] = rand()*(float)1.1; }
if((retval=PAPI_flops( &real_time, &proc_time, &flpins, &mflops))<PAPI_OK)
test_fail(__FILE__, __LINE__, "PAPI_flops", retval);
for (i=0;i<INDEX;i++)
{
for(j=0;j<INDEX;j++)
{
for(k=0;k<INDEX;k++)
{
mresult[i][j]=mresult[i][j] + matrixa[i][k]*matrixb[k][j];
}
}
}
if((retval=PAPI_flops( &real_time, &proc_time, &flpins, &mflops)) <PAPI_OK)
{
test_fail(__FILE__, __LINE__, "PAPI_flops", retval);
}
fprintf(file,"Real_time:\t%f\nProc_time:\t%f\nTotal flpins:\t%lld \nMFLOPS:\t\t%f\n",
real_time, proc_time, flpins, mflops); //cannot see this output in the `output.txt` file
fflush(file);
fprintf(file,"%s\tPASSED\n", __FILE__);
fflush(file);
fclose(file);
PAPI_shutdown();
exit(0);
}
static void test_fail(char *file, int line, char *call, int retval){
}
In the output file, I only see the lines for "State is now". I don't see the outputs for "Real_time:\t%f\nProc_time:\t%f\nTotal flpins:\t%lld \nMFLOPS and the other outputs. I tried to use fflush, but that didn't help either. Anyone know what is going on?

Related

Reading GPS data from Serial Port Ubuntu

I'm trying to read the GPS data from a serial port, at the moment i can read the data. But im trying to get only the data from "$GPRMC" line only.
I have this code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include <sys/ioctl.h>
int main(int argc, char** argv) {
int sfd = open("/dev/ttyUSB0", O_RDWR | O_NOCTTY);
if (sfd == -1) {
printf("Error no is : %d\n", errno);
printf("Error description is : %s\n", strerror(errno));
return (-1);
};
struct termios options;
tcgetattr(sfd, &options);
cfsetspeed(&options, B9600);
cfmakeraw(&options);
//options.c_cc[VTIME]=1;
//options.c_cc[VMIN]=100;
//tcflush(sfd, TCIFLUSH);
tcsetattr(sfd, TCSANOW, &options);
usleep(100000);
char serialBuffer[500];
int bytes;
int count;
ioctl(sfd, FIONREAD, &bytes);
int i =0;
char *ret;
char *sepa;
char sepa2[500];
int compare;
for(;;){
if(bytes!=0){
count = read(sfd, serialBuffer, sizeof(serialBuffer));
}
if (count == -1){
printf("ERROR");
break;
}
else if(count == 0){
printf("NODATA");
break;
}
else{
serialBuffer[count] = '\0';
//strcpy(serialBuffer2, serialBuffer);
//printf("%s,", serialBuffer);
sepa = strtok(serialBuffer, "\n");
while(sepa != NULL){
//printf("%s", sepa);
//strcpy(serialBuffer2, sepa);
sepa = strtok(NULL, "\n");
ret = strstr(sepa, "$GPRMC");
if (NULL != ret) {
printf("The substring is: %s\n", ret);
}
}
}
}
close(sfd);
return (EXIT_SUCCESS);
}
This script is always returning me "Segmentation Faul(Core Dumped)", and i dont know why. Im new at c, can any one help me on this?
Thanks

Linux kernel module - IOCTL usage returns ENOTTY

Im working on little kernel module. Im trying to use IOCTL (in ioctl_add), but I get ENOTTY when I call it, which is checked in switch, on the bottom of main. The code is below. Has anyone got any idea what am I doing wrong?
user.c:
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <linux/ioctl.h>
#include <sys/stat.h>
#include <sys/poll.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#define IOCTL_TYPE (100)
#define IOCTL_ADD (_IO(IOCTL_TYPE, 1))
void cleanup()
{
if(f>=0) {
close(f);
}
}
int ioctl_add(int f)
{
int ret;
ret = ioctl(f, IOCTL_ADD);
printf("Add \n");
return ret;
}
int main(int argc, char * argv[])
{
int fd;
int *ptr;
fd = open(argv[1], O_RDWR);
if (fd < 0) {
perror("error");
}
posix_memalign((void **)&ptr, 4096, 4096);
* ptr = atoi(argv[2]);
write(fd, ptr, 4096);
ioctl_add(fd);
printf("data is %d\n", *ptr);
close(fd);
switch(errno){
case EBADF:
printf("errno: EBADF \n");
break;
case EFAULT:
printf("errno: EFAULT \n");
break;
case EINVAL:
printf("errno: EINVAL \n");
break;
case ENOTTY:
printf("errno: ENOTTY \n");
break;
default:
printf("errno: none \n");
return 0;
}
return 0;
}
module.c:
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/cdev.h>
//#include <linux/mm.h>
//#include <linux/config.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/poll.h>
#include <asm/io.h>
#include <asm/bitops.h>
#include <linux/ioctl.h>
#define IOCTL_TYPE (100)
#define IOCTL_ADD (_IO(IOCTL_TYPE, 1))
#include <linux/mm.h>
#include <linux/pagemap.h>
#define DEVICE_NAME "acc_priv"
MODULE_LICENSE("GPL v2");
int ress, tmp;
struct page *page;
int *myaddr;
ssize_t acc_read(struct file *filp,
char __user *buf, size_t count,loff_t * off)
{
printk (KERN_ALERT "Opened\n\r");
return 0;
}
ssize_t acc_write(struct file *filp,
const char __user *buf, size_t count,loff_t * off)
{
printk (KERN_ALERT "Write\n\r");
printk(KERN_INFO "%s\n", __FUNCTION__);
down_read(&current->mm->mmap_sem);
ress = get_user_pages(current, current->mm,(unsigned long)buf,1,1,1,&page,NULL);
if (ress) {
printk(KERN_INFO "Got mmaped.\n");
myaddr = kmap(page);
printk(KERN_INFO "%d\n", *myaddr);
tmp = *myaddr;
tmp = tmp * 2;
printk(KERN_INFO "the result of multiplying: %d\n", tmp);
* myaddr = tmp;
page_cache_release(page);
}
up_read(&current->mm->mmap_sem);
return (0);
}
static int acc_open(struct inode *inode,
struct file *file)
{
printk(KERN_INFO "Opened inode:%p, file:%p\n", inode, file);
return 0;
}
long acc_ioctl(struct file *filp,
unsigned int cmd,unsigned long arg)
{
if(cmd == IOCTL_ADD)
printk(KERN_INFO "Do specified job \n");
return 0;
{
int acc_release(struct inode *inode,
struct file *file)
{
printk (KERN_INFO "device_release(%p,%p)\n", inode, file);
return 0;
}
struct file_operations Fops = {
.owner=THIS_MODULE,
.read=acc_read,
.write=acc_write,
.open=acc_open,
.unlocked_ioctl=acc_ioctl,
.release=acc_release,
};
dev_t my_dev=0;
struct cdev * my_cdev = NULL;
static struct class *class_acc_priv = NULL;
void clean_up(void)
{
if(my_dev && class_acc_priv) {
device_destroy(class_acc_priv,my_dev);
}
if(my_cdev) {
cdev_del(my_cdev);
my_cdev=NULL;
}
if(my_dev) {
unregister_chrdev_region(my_dev, 1);
}
if(class_acc_priv) {
class_destroy(class_acc_priv);
class_acc_priv=NULL;
}
}
int init_acc_priv(void)
{
int res=0;
res=alloc_chrdev_region(&my_dev, 0, 1, DEVICE_NAME);
if(res) {
printk (KERN_ALERT "Alocation of the device number for %s failed\n",
DEVICE_NAME);
return res;
};
class_acc_priv = class_create(THIS_MODULE, "acc_class");
if (IS_ERR(class_acc_priv)) {
printk(KERN_ERR "Error creating rs_class.\n");
res=PTR_ERR(class_acc_priv);
goto err1;
}
my_cdev = cdev_alloc( );
my_cdev->ops = &Fops;
my_cdev->owner = THIS_MODULE;
res=cdev_add(my_cdev, my_dev, 1);
if(res) {
printk (KERN_ALERT "Registration of the device number for %s failed\n",
DEVICE_NAME);
res=-EFAULT;
goto err1;
};
device_create(class_acc_priv,NULL,my_dev,NULL,"acc_priv%d",MINOR(my_dev));
printk (KERN_ALERT "%s The major device number is %d.\n",
"Registeration is a success.",
MAJOR(my_dev));
return res;
err1:
clean_up();
return res;
}
module_init(init_acc_priv);
void cleanup_acc_priv( void )
{
clean_up();
}
module_exit(cleanup_acc_priv);
When 32bit application is run on 64bit OS, it uses compat_ioctl syscall instead of unlocked_ioctl one for perform ioctl command. The reason of special syscall is that size of ioctl argument may differ for 64bit and 32bit applications.
So you need to implement .compat_ioctl file operation.

PulseAudio:sound recorded but plays annoying sound

I'm new with PulseAudio. I'm trying to make simple programs. One would record the sound and save it in baniry file, and the other one should open it and play. Here is my code for recording:
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <pulse/simple.h>
#include <pulse/error.h>
#define BUFSIZE 32
int main(int argc, char*argv[])
{
/* The Sample format to use */
static const pa_sample_spec ss = {
.format = PA_SAMPLE_S16LE, //16bit iqneba agwerili tito sample
.rate = 44100, //number of samples played in each second
.channels = 2
};
pa_simple *s_in = NULL;
int ret = 1;
int error;
int siri =0;
//file info
FILE* pFile;
char* yourFilePath = "xma.bin";
pFile = fopen(yourFilePath,"wb");
if (!(s_in = pa_simple_new(NULL, argv[0], PA_STREAM_RECORD, NULL, "record", &ss, NULL, NULL, &error)))
{
fprintf(stderr, __FILE__": pa_simple_new() failed: %s\n", pa_strerror(error));
goto finish;
}
for (;siri<10000;siri+=1)
{
uint8_t buf[BUFSIZE];
ssize_t r;
int yorBufferSize = strlen(buf) + 1;
/* Write your buffer to disk. */
if (pa_simple_read(s_in, buf, sizeof(buf), &error) < 0)
{
fprintf(stderr, __FILE__": read() failed: %s\n", strerror(errno));
goto finish;
}
if (pFile)
{
fwrite(buf, yorBufferSize, 1, pFile);
puts("Wrote to file!");
}
else
{
puts("Something wrong writing to File.");
}
}
ret = 0;
finish:
if (s_in)
pa_simple_free(s_in);
return ret;
fclose(pFile);
}
And here is my recording program:
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <pulse/simple.h>
#include <pulse/error.h>
#define BUFSIZE 32
int main(int argc, char*argv[])
{
/* The Sample format to use */
static const pa_sample_spec ss = {
.format = PA_SAMPLE_S16LE, //16bit iqneba agwerili tito sample
.rate = 44100, //number of samples played in each second
.channels = 2
};
pa_simple *s_out = NULL;
int ret = 1;
int error;
//file info
FILE* pFile;
char* yourFilePath = "xma.bin";
pFile = fopen(yourFilePath, "rb");
/* Create a new playback stream */
if (!(s_out = pa_simple_new(NULL, argv[0], PA_STREAM_PLAYBACK, NULL, "playback", &ss, NULL, NULL, &error)))
{
fprintf(stderr, __FILE__": pa_simple_new() failed: %s\n", pa_strerror(error));
goto finish;
}
for (;;)
{
uint8_t buf[BUFSIZE];
fread(buf, sizeof(buf), 1, pFile);
ssize_t r;
if(feof(pFile))
{
break;
}
printf("%x", buf);
/* ... and play it */
if (pa_simple_write(s_out, buf, sizeof(buf), &error) < 0)
{
fprintf(stderr, __FILE__": pa_simple_write() failed: %s\n", pa_strerror(error));
goto finish;
}
}
/* Make sure that every single sample was played */
if (pa_simple_drain(s_out, &error) < 0)
{
fprintf(stderr, __FILE__": pa_simple_drain() failed: %s\n", pa_strerror(error));
goto finish;
}
ret = 0;
finish:
if (s_out)
pa_simple_free(s_out);
return ret;
fclose(pFile);
}
For loop in record program is just for time to record something(could not figure out how to set a timer) and I know that I should not use gotos but its for educational purposes(example provided on PulseAudio website). I tried hexdump of xma.bin and it gave me totally different ouput
than printf("%x", buf); Basically printf only gives back bf9fe15c repeatedly and it make annoying sound. Hope you can help. thanks.
I deleted pa_simple_drain() (it was my mistake that i used this function in recording program)function from record program and now it works. But in printf("%x", buf) it still gives me back same hex value over and over again. But programs work great. Can someone exmplain why does it print same value?

Getting retval, cleanup, destroy failed using Papi

I am trying to test out using papi, but I am getting some errors that I don't understand why they're occurring. I couldn't find anything online for them. The code is below
I am using PAPI and C.
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <memory.h>
#include <malloc.h>
#include "papi.h"
#define INDEX 100
static void test_fail(char *file, int line, char *call, int retval);
int main(int argc, char **argv) {
extern void dummy(void *);
float matrixa[INDEX][INDEX], matrixb[INDEX][INDEX], mresult[INDEX] [INDEX];
float real_time, proc_time, mflops;
long long flpins;
int retval, status = 0;
int i,j,k;
long_long values[1];
FILE *file;
file = fopen("output.txt","w");
retval = PAPI_library_init(PAPI_VER_CURRENT);
int EventSet = PAPI_NULL;
PAPI_create_eventset(&EventSet);
if(PAPI_add_event(EventSet, PAPI_LD_INS) != PAPI_OK)
{
fprintf(file,"PAPI failed to add Load/Store instructions\n");
}
if (PAPI_state(EventSet, &status) != PAPI_OK)
fprintf(file,"state fail\n");
fprintf(file, "State is now %d\n", status);
if (PAPI_start(EventSet) != PAPI_OK)
fprintf(file,"start fail\n");
if (PAPI_state(EventSet, &status) != PAPI_OK)
fprintf(file,"state2 fail\n");
fprintf(file, "State is now %d\n", status);
/* Initialize the Matrix arrays */
for ( i=0; i<INDEX; i++ ){
mresult[0][i] = 0.0;
matrixa[0][i] = matrixb[0][i] = rand()*(float)1.1; }
if((retval=PAPI_flops( &real_time, &proc_time, &flpins, &mflops))<PAPI_OK)
fprintf(file,"retval failed\n");
for (i=0;i<INDEX;i++)
{
for(j=0;j<INDEX;j++)
{
for(k=0;k<INDEX;k++)
{
mresult[i][j]=mresult[i][j] + matrixa[i][k]*matrixb[k][j];
}
}
}
if((retval=PAPI_flops( &real_time, &proc_time, &flpins, &mflops)) <PAPI_OK)
{
fprintf(infile,"ret2 failed\n");
}
fprintf(file,"Real_time:\t%f\nProc_time:\t%f\nTotal flpins:\t%lld \nMFLOPS:\t\t%f\n",
real_time, proc_time, flpins, mflops);
fflush(file);
fprintf(file,"%s\tPASSED\n", __FILE__);
fflush(file);
if (PAPI_read(EventSet, values) != PAPI_OK)
{fprintf(file,"read fail\n");}
if (PAPI_stop(EventSet, values) != PAPI_OK)
{fprintf(file,"stop fail\n");}
if (PAPI_cleanup_eventset(&EventSet) != PAPI_OK)
{fprintf(file,"cleanup fail\n");}
if (PAPI_destroy_eventset(&EventSet) != PAPI_OK)
{fprintf(file,"destroy fail\n");}
fprintf(file,"\nValues is %f\n", values[0]);
fflush(file);
fclose(file);
PAPI_shutdown();
exit(0);
}
In the output file, I just see the below:
State is now 1
State is now 2
retval failed
ret2 failed
Real_time: 0.000000
Proc_time: 0.000000
Total flpins: 99
MFLOPS: 0.000000
PAPI_flops.c PASSED
cleanup fail
destroy fail
I don't understand why ret, ret2, cleanup and destroy failed. Why?
You can use the PAPI_perror or PAPI_strerror functions to get the error message associated with an error return value. This may help track down why, for example, PAPI_flops is failing. (It could be that there is no support on your system for the required events.)
The reason why PAPI_cleanup_eventset is failing though is because it takes just the integer EventSet, not a pointer to it.
I'd strongly recommend emitting the error return value strings, and also compiling with warnings on — the latter would likely have found the issue with the wrong parameter type.

Convert Linux C Char Array to Int

need some advice on this one as im struggling abit and cannot figure it out.
i have a file that gets updated on a PC to indicate a system ran and what time it ran. i am writing a very simple linux console app (will eventually be a nagios plugin). that reads this file and responds depending on what it found within the file.
i am a total newbie to programming on Linux and using C so please be patient and if you would explain any answers it would really be appreciated.
basically i want to convert a char array containing 5 characters into an integer, however the 5th char in the array is always a letter. so technically all i want to-do is convert the first 4 chars in the array to a integer... how?? ive tried multiple ways with no success, my problem is that presently i do not have a good grasp of the language so have no real ideas on what it can and cannot do.
here is the source to my program.
basically the buf array will be holding a string taken from the file that will look something like this
3455Y (the number will be random but always 4 chars long).
Sorry for the poor formatting of the code, but i cannot get this stupid window for love nor money to format it correctly....
include <fcntl.h>
include <unistd.h>
include <stdio.h>
include <stdlib.h>
include <time.h>
include <string.h>
define COPYMODE 0644
int main(int argc, char *argv[])
{
int i, nRead, fd;
int source;
int STATE_OK = 0;
int STATE_WARNING = 1;
int STATE_CRITICAL = 2;
int STATE_UNKNOWN = 3;
int system_paused = 0;
char buf[5];
int testnumber;
if((fd = open(argv[1], O_RDONLY)) == -1)
{
printf("failed open : %s", argv[1]);
return STATE_UNKNOWN;
}
else
{
nRead = read(fd, buf, 5);
}
close(source);
if (buf[4] == 'P')
{
printf("Software Paused");
return STATE_WARNING;
}
else
{
return STATE_OK;
}
time_t ltime; /* calendar time */
struct tm *Tm;
ltime=time(NULL); /* get current cal time */
Tm=localtime(&ltime);
int test;
test = Tm->tm_hour + Tm->tm_min;
printf("%d", test);
printf("%d", strtoi(buf));
}
You can use sscanf to do the job:
int num = 0;
sscanf(buf, "%4d", &num);
Then num should hold the number from the line in the file.
You can use atoi
atoi requires one char * argument and returns an int.
If the string is empty, or first character isn't a number or a minus sign, then atoi returns 0.If atoi encounters a non-number character, it returns the number formed up until that point
int num = atoi(buf);
if you want to convert the first four characters of a string to an integer do this:
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdint.h>
uint8_t convertFirstFourChars(char * str, uint32_t *value){
char tmp[5] = {0};
strncpy((char *) tmp, str, 4);
*value = strtoul(tmp);
return errno;
}
then call / test this function like this
#include <stdint.h>
#include <stdio.h>
int main(int argc, char **argv){
char test1[5] = "1234A";
char test2[5] = "ABCDE";
uint32_t val = 0;
if(convertFirstFourChars((char *) test1, &val) == 0){
printf("conversion of %s succeeded, value = %ld\n", test1, val);
}
else{
printf("conversion of %s failed!\n", test1);
}
if(convertFirstFourChars((char *) test2, &val) == 0){
printf("conversion succeeded of %s, value = %ld\n", test2, val);
}
else{
printf("conversion of %s failed!\n", test2);
}
return 0;
}
FWIW, don't use atoi(...) because it converts any string to an integer regardless of its validity as a number. atoi("foo") === 0.
this is as much of your code as I was able to recover from the formatting:
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <time.h>
#define COPYMODE 0644
int main(int argc, char *argv[])
{
int i, nRead, fd;
int source;
int STATE_OK = 0;
int STATE_WARNING = 1;
int STATE_CRITICAL = 2;
int STATE_UNKNOWN = 3;
int system_paused = 0;
char buf[5];
int testnumber;
if((fd = open(argv[1], O_RDONLY)) == -1)
{
printf("failed open : %s", argv[1]);
return STATE_UNKNOWN;
}
else
{
nRead = read(fd, buf, 5);
}
close(source);
if (buf[4] == 'P')
{
printf("Software Paused");
return STATE_WARNING;
} else {
return STATE_OK;
}
time_t ltime; /* calendar time /
struct tm Tm;
ltime=time(NULL); / get current cal time */
Tm=localtime(&ltime);
int test;
test = Tm->tm_hour + Tm->tm_min;
printf("%d", test);
printf("%d", strtoi(buf));
}
this is the version that does what you specified:
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <time.h>
#define COPYMODE 0644
int main(int argc, char *argv[])
{
int i, nRead, fd;
int source;
int STATE_OK = 0;
int STATE_WARNING = 1;
int STATE_CRITICAL = 2;
int STATE_UNKNOWN = 3;
int system_paused = 0;
char buf[5];
int testnumber;
if((fd = open(argv[1], O_RDONLY)) == -1)
{
printf("failed open : %s", argv[1]);
return STATE_UNKNOWN;
}
else
{
nRead = read(fd, buf, 5);
}
close(source);
if (buf[4] == 'P')
{
printf("Software Paused");
return STATE_WARNING;
}/* else {
return STATE_OK;
buf[4] = 0;
} */
time_t ltime; /* calendar time */
struct tm *Tm;
ltime=time(NULL); /* get current cal time */
Tm=localtime(&ltime);
int test;
test = Tm->tm_hour + Tm->tm_min;
printf("%d\n", test);
printf("%d\n", atoi(buf));
}
The biggest problem with your code was the if statement with the returns in each branch, insuring that nothing after the if statement was ever executed.

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