705 questions
0
votes
2
answers
67
views
C strlen() returns the wrong String length (character count) when using umlauts [duplicate]
I'm working on a C program, which takes an input in form of a parameter and then needs the length of the string to continue its work.
Unfortunately I'm facing a massive issue in form of a wrong ...
- 353
1
vote
2
answers
69
views
Unable to get length of arg - C [closed]
basically I'm trying to get the length (using strlen) of an argument, but i keep getting this error. From what I've understood it means that I'm giving an array of pointers to char arrays instead of a ...
- 23
2
votes
3
answers
160
views
Why is the strlen here equal to 25?
Just so I can confirm if what I think is going on is really going on. The following code prints out 25 when i give it the (26 letter) alphabet as an input, is it 'cause fgets always automatically sets ...
2
votes
1
answer
127
views
Why doesn't the compiler optimize strlen() calls in a loop, despite it being a pure function? And how would [[reproducible]] affect this?
I have two functions that convert a string to lowercase. The first one calls strlen() in every iteration, while the second one only calls it after modifying the string. I expected the compiler to ...
- 83
2
votes
3
answers
121
views
C strlen on char array
I'm new to programming, so I was practicing with C. Then I ran to a problem with my code:
#include <stdio.h>
#include <string.h>
int main()
{
char a[] = "Hello";
printf(&...
- 23
0
votes
1
answer
73
views
User input sanitization program, which takes a specific amount of arguments and passes the execution to a bash script
I am trying to write a little program, which is resistant against buffer overflow and similar vulnerabilities.
Since we cannot trust the user input, I thought it would be a good idea to concatenate ...
- 321
4
votes
0
answers
95
views
Is there a better way to search any byte from a long value?
In OPENJDK's StringSupport class, there are following codes checking if there could be a '\0' byte in a long value:
private static final long HIMAGIC_FOR_BYTES = 0x8080_8080_8080_8080L;
private static ...
- 307
3
votes
1
answer
159
views
Strlen function giving wrong length when there are non-english characters in string
I have a program that accepts non-english characters also as an input field. Because we use strlen, it has failed to give expected length while calculating the length of the string when there is a non-...
- 39
0
votes
0
answers
99
views
add_action hook is not working on user_register in wordpress
I have a wordpress site, and my registration url is Registration URL.
I have registered a hook to modify user_login after registration if username is more than 10 digits.
if user given mobile number ...
1
vote
1
answer
100
views
c++, How to display an error if user inputs more than one char
I have been trying to find a solution for my school project. The program should display an invalid error if the user enters "Y Y". Currently the program still accepts it and moves on to the ...
- 13
0
votes
1
answer
138
views
Why +1 in realloc for string in C? If it's for null terminator, then how does strlen() measures len of the str if there's no null byte at the end? [duplicate]
This code is from a problem in HackerRank (Q: Printing Tokens in C).
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main() {
char *s = malloc(1024 * sizeof(char))...
- 15
0
votes
1
answer
71
views
Casting from int array to char pointer in C
int v_1[10] = { -1,1000,2 };
int a;
a = strlen(((char*)v_1 + 1));
I'm having trouble understanding why the 'a' variable is equal to 5 in this particular case.
I'm also struggling to grasp the ...
- 13
-1
votes
2
answers
166
views
Why is "-1 < strlen(s)" equal to 0?
char* s =(char*) "sss";
int j = -1;
printf("%d", j < strlen(s));
It's mainly about the difference between j < 3 and j < strlen(s).
In the above code, the printf() ...
- 19
0
votes
0
answers
54
views
Why is the string length of buf1[12] = "hello world?" 13? [duplicate]
I have the code and output below, why are the string length of buf1 and buf2/buf3 different?
#include <stdio.h>
#include <string.h>
int main() {
char buf1[12] = "hello world?&...
- 11
0
votes
2
answers
48
views
String concatenation not working properly in C using sizeof() but it works for strlen() [duplicate]
#include <stdio.h>
int main(void) {
char strp[] = "hello";
char strq[] = " world";
strcat(strp,strq);
puts(strp); //hello world
printf("%d",...
0
votes
2
answers
140
views
Unsigned char* instead of char*
Why most c functions with string in param usually has definition char* and not unsigned char*? According to my understanding unsigned char* is more generic.
And how to deal in situations when I have ...
- 18.1k
0
votes
1
answer
157
views
When the parameter of strlen is a non zero terminated string, its return value is unsafe in IF statesments?
I have been troubled by a problem of strlen for a long time, here is the code:
char stack_protect[1000] = {0};
char temp[100] = { 0 };
memset(&temp, 1, 110);
int len = strlen(temp);
...
1
vote
0
answers
157
views
Is strlen() not actually located in the DLL/Static library?
I was trying to assess effectiveness of my custom strlen() implementation versus the default C function.
inline ui64 Sl(const char *cs)
{
const char *sbeg = cs--;
while(*(++cs) != 0)
{
...
1
vote
1
answer
356
views
Speed up strlen using SWAR in x86-64 assembly
The asm function strlen receives the link to a string as a char - Array. To to so, the function may use SWAR on general purpose register, but without using xmm register or SSE instructions.
The ...
- 398
0
votes
0
answers
47
views
page fault error with SIMD strlen (using SWAR in integer registers, not SSE) [duplicate]
The asm function strlen receives the link to an string as a char - Array. To to so, the functions may use SIMD on general purpose register, but without using xmm register or SSE instructions.
The ...
- 398
-1
votes
3
answers
123
views
Why strlen() is giving wrong value for a char array with undefined array size?
#include<stdio.h>
#include<string.h>
int main(){
int a[]={1,2,3,4};
int size= sizeof(a)/sizeof(int);
printf("\nSize/capacity of integer type array(with no limit) %d\n",size)...
- 11
-7
votes
1
answer
103
views
strcmp always returns 1 even if it ie equal [closed]
it always returns 1 even if they aren't same
and im wondering that why i have to write down buffer size in scanf_s
if i don't the scnaf_s does not work
int main(void) {
char str1[30] = "push&...
- 1
1
vote
1
answer
39
views
Extra characters appearing when pthread_create is called with a struct as an argument to the thread
I observed that when I pass a struct as an argument to the thread, the string member of the struct is few characters longer inside the thread.
So basically, in main, s-dev is 12 characters long. And ...
- 283
-1
votes
2
answers
120
views
in dev c++ my library is missing how to install it [closed]
//my code is
#include <stdio.h>
int main() {
char txt[] = "xyz";
printf("%d", strlen(txt));
return 0;
}
//error is strlen is not declared in this scope
//it should work my ...
0
votes
3
answers
155
views
Understand Strlen applied to int array with char * cast
I'm currently stuck on this problem.
I have thefollowing code:
int v[10] = {-1, 1000, 2};
int a;
a = strlen((char *)v+1);
printf("strlen result for (char *) v+1: %d\...
- 81
-1
votes
3
answers
799
views
Understanding parameters of strlen in C
I am a bit confused on why my code is not iterating a string in C programming.
Essentially.
I have this function here
int atoi(const char *s[]){
printf(" The length is %d",strlen(s));
...
0
votes
2
answers
60
views
Wrong strlen returning char Matrix
char t[2][5] = {" * "," * "};
printf("%d\n",strlen(t[0]));
Output:
11
Why is this happening and how can I print just the length of the first string?
Each string ...
- 1,849
3
votes
1
answer
15k
views
Depreciated strlen(): Passing null to parameter #1 ($string) of type string is depreciated
your text
The above warning is displayed in PHP 8.1 after upgrading from PHP 7.4
Any ideas on how this code can be changed for PHP 8.1 compatibility?
private function cleanInput2($strRawText, $...
- 53
0
votes
0
answers
37
views
How to prevent my code to count `\0` as one character? [duplicate]
I'm attempting to make strlen in C standard library on my own.
Following is my code and the strlen func I made is given the name mystrlen in the script below.
#include <stdio.h>
//int ...
- 11
-1
votes
2
answers
131
views
Segmentation fault 11 when making strlen in my own
I am trying to create strlen in C's standard library by myself like following, named it mystrlen. I added other parts to make it run.
I used vim editor to write the code and gcc to run the code. The ...
- 11
0
votes
1
answer
87
views
"while ( strlen($tmppwd) < 20 )..." returns strings shorter than 20 characters
I am trying to generate a random string in the exact length of 20 characters and getting unexpected behavior from my program,
so curious about what I am missing.
Here is the code:
<?php
$tmppwd ...
- 1
-2
votes
4
answers
713
views
Modify itoa to process a floating point string with decimal point operator into ASCII char 23(123.456) in the output
Having trouble C language debug step into process decimal point operator in a floating point sting of numbers.
Example: 1234.5678, itoa() output stops at 4 and terminates out array string with '\0' ...
-2
votes
1
answer
192
views
How to run php strlen function on entire array? [duplicate]
I have an array of strings, and I want to find the sum of the lengths of all the strings in the array. Eg:
$array = ['One', 'Two', 'Three'];
strlen result is
3 3 5
and the sum is 11. How can this be ...
- 27
0
votes
2
answers
199
views
Understanding code of function strlen in C Programming
I was given a solution to the problem of recreating the function strlen in C Programming and it was the following, I need help understanding what the code is actually doing.
void *ft_memset(void *b,...
1
vote
2
answers
132
views
Count consonants in a word randomly found in an array
I want to take a random string of the array and should count the consonants of the random string.
Problem is it did not count the letters from array_rand().
Here is what I get at this point:
$woerter =...
- 13
0
votes
2
answers
336
views
Strlen() Vs Strcmp for checking empty char array variable
#include <iostream>
#include <cstring>
int main()
{
char c1[5];
char c2[5];
if ( strlen(c1) == 0)
{
std::cout<<" c1 empty";
}
if (strcmp(...
- 1,150
1
vote
1
answer
154
views
Why are the standard library functions so fast?
I wrote a simple code to test mystrlen by comparing it to the standard library strlen on a 2089360 byte string. I used two versions of mystrlen and both are very far from the standard strlen runtime, ...
- 15
-4
votes
1
answer
347
views
.length(), strlen(n), and sizeof(n) does not work with string and cstring [closed]
I'm trying to write code that outputs the length of a string.
int main(){
string s1, s2;
scanf("%s %s", &s1, &s2); //Doesn't work.
cin >> s1, s2; //Works, I inputed ...
1
vote
1
answer
77
views
"strlen" does not give the exact number of characters
I have a WordPress Template with a loop of articles where I want to show the characters that every articles have. I do it this way:
<?php $length = strlen( utf8_decode( get_the_content() ) ); echo $...
- 1,828
0
votes
3
answers
165
views
Trying to output the length of a string using strlen() through a pointer
I am trying to output the length of a string using strlen(). But I want to do it through a pointer.
Here's what I tried:
`
#include <stdio.h>
#include <string.h>
int main()
{
char a[]=...
- 27
0
votes
0
answers
361
views
I have a problem with finding end of string in assembly
the code:
.text
_start: .global _start
mov r2, #0
adr r1, msg
ldrb r5, =newline
getlen:
ldrb r3, [r1,r2]
add r2, r2, #1
cmp r3, r5
bne getlen
p:
...
- 35
0
votes
1
answer
79
views
Why is strlen conting the null character here? [duplicate]
Normaly strlen does not count the null terminator at the end of the string. But the below code prints the string count with the null terminator. Can anyone explain me why?
int main(){
char name[...
- 13
0
votes
2
answers
124
views
How to get array length for array of strings
I want to find the number of elements in that array, but as far as I know I'm not allowed to use strlen or sizeof. strlen(array[0]) gives out 5 cause apple consists of 5 characters, but I need length ...
- 27
0
votes
1
answer
534
views
Data Matrix Barcode split to different data
I have a data matrix barcode that have the input
Data Matrix Barcode = 0109556135082301172207211060221967 21Sk4YGvF811210721
I wish to have output as below:-
Items
Output
Gtin
09556135082301
Expire ...
- 55
0
votes
1
answer
238
views
How to get string length in function
How can I get the length of the buffer in the function using pointers?
#include <stdio.h>
#include <stdlib.h>
void fun(char *(buffer))
{
printf(strlen(buffer));
}
int main()
{
...
user19986697
0
votes
0
answers
65
views
what is the NOT instruction doing to eax in assembly [duplicate]
repnz scas al,BYTE PTR es:[edi
MOV eax,ecx
NOT eax
value of eax changed from 0xfffffffc to 0x3 after these lines.
- 1
1
vote
5
answers
725
views
Is it faster to use strlen() than just check for null character in a for loop?
I've only been able to find two posts related to this topic. In one post, the code in question was written such that strlen() was called in every iteration of the loop, which many users pointed out ...
0
votes
2
answers
289
views
Inaccurate length of string when using 'strlen'
I am getting inaccurate string length when printing the length of a string using the strlen function.
I am getting the output for string a as 5 (which is correct), but when I am printing the length of ...
-1
votes
1
answer
48
views
comparing string repetitively returns wrong value
In the below program I am trying to copy string data "eth0" into the array of structure containing string data and a count defined as below.
strcmp returns true for the first index but for ...
user7809950
1
vote
2
answers
1k
views
Recursion to find length of a string in C
I am trying to find the length of a string by recursion using the following code:
#include <stdio.h>
int string_length(char *s, int x);
int main(void)
{
int length = 0, x;
char string[] ...
- 339