All Questions
5,948
questions
2
votes
2
answers
57
views
Using printf from c in Nasm causes the string to add random end line statment
this morning i tried to make a simple output library for my asm projects, i realized using the sys call each time is a waste of time and so i decided to automatize the program using printf function ...
- 35
3
votes
2
answers
85
views
Interpreting the format specifier in printf("%.-1f", 34.14)
Consider the following invocation of printf():
printf("%.-1f", 34.14);
it specifies a negative precision value of -1. Making this call with glibc, we get:
%0.-1f
is this correct? If so, ...
- 127k
1
vote
1
answer
58
views
format string and vararg - can I tell compiler to check them?
I have the following function for Logging purposes:
void LogE(const char* scope, const char* s, ...) {
fprintf(stderr, "%s : ", scope);
va_list list;
va_start(list, s);
...
- 4,468
1
vote
1
answer
67
views
Why does printf flush or not flush depending on where the line is in a loop?
Why, in this program, does the printf function print or not print depending on where it is inside the loop?
#include <stdio.h>
#include <time.h>
int main()
{
char frames[] = {'-',...
- 98
0
votes
0
answers
60
views
Why does my printf function not work? Is my while loop not ending? [duplicate]
I am just trying to copy and paste the text input. After which the code must show done.
#include <stdio.h>
/*code to copy all input characters and paste it one by one*/
int main()
{
int c;
...
1
vote
3
answers
93
views
Does s conversion specifier specify direction / order in which characters are written?
Does s conversion specifier specify direction / order in which characters are written?
N3220 working draft, 7.23.6p8 (emphasis added):
s If no l length modifier is present, the argument shall be a ...
- 5,951
-1
votes
1
answer
67
views
getchar() taking stuff which I print using printf()
#include <stdio.h>
int main() {
int c;
for (int i = 0; i < 10; i++) {
c = (getchar() != EOF);
printf("%d\n", c);
}
printf("As we can see, the value of c is ...
- 52
0
votes
3
answers
116
views
Using the malloc function once initializes all uninitialized variables with a 0
The malloc function is not supposed to initialize any value to any variable it is used on, like the calloc function does. Why then do I keep getting the initialized value of even other varibales to ...
0
votes
0
answers
36
views
What happens when you missout an argument to the printf function [duplicate]
The following code prints out the Celsius equivalent of Fahrenheit temperatures from 0 to 300 with 20 as step.
#include <stdio.h>
int main(void) {
int fahr, celsius;
int lower, upper, ...
- 133
0
votes
1
answer
40
views
Printing negative value as long with %ld in printf(3) results in an unsigned output, except with explicit type cast... Why?
Here are some tests I did
printf("%ld", -1); // output 4294967295 (UINT_MAX)
printf("%ld", (long) -1); // output -1
So why does it print UINT_MAX instead of actual -1 without the ...
- 11
0
votes
0
answers
78
views
C program does not write data to the file properly
My code is as follows:
#define MAX_ELEMENTS 100
#define MAXIMUM_LENGTH 50
typedef struct {
char teacher;
int id;
char day[MAXIMUM_LENGTH];
char startingTime[MAXIMUM_LENGTH];
...
- 1
0
votes
1
answer
96
views
STM32, arm-none-eabi: String is not output with printf if the string contains a leading `\n`
In my STM32 application I have the following code in main:
printf("\nRunning Smoke Tests...\n");
The problem is that the whole string is not sent via UART. With some testing I found out that ...
- 25
3
votes
1
answer
73
views
Strange printf not working after a getchar and getchar skipping
I'm getting crazy with C.
I'm programming with JavaScript, Ruby, Python, PHP, Lua, even Java...
Recently, I tried to program a simple Read-Eval-Print-Loop in C.
And I have a very strange behavior with ...
- 81
1
vote
1
answer
59
views
How to know how many argument vsnprintf has used, if buffer size is less than actual size needed?
I am trying to break the message into chunks of 32bytes, i am using vsnprintf to print the message. But the args are not incrementing i.e. even after calling vsnprintf the args show the first argument....
- 41
1
vote
1
answer
81
views
Expression evaluation in printf with %p
I am studying pointers in C. Trying a bunch of things to make sure I understand how pointers work, I found something that I don't understand. Here's the snippet of the code in question:
int b = 30;
...
- 23