A standard C function that returns the length of a string.
This function calculates the length of the string, excluding the terminating null byte \0. It is defined in the <string.h> standard header.
Questions tagged [strlen]
692 questions
4
votes
3 answers
Bus error while running a simple string C program
I was running this simple program, the output i get is a "bus error". using some debugging statements i found the point at which it occurs was at the strcat() call.
#include
#include
main()
{
char *s = "this is ";
char *s1 = "me";…
Maverickgugu
- 767
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4
votes
1 answer
Get C string length of a 16 or 32-byte fixed-size buffer? (XMM or YMM register width)
Is there any way to get the length of an ASCII string that is stored in a 16- or 32-byte buffer by loading it into an XMM or YMM register?
Essentially I am looking for the index (in bits or bytes) of the first zero byte.
My goal is to avoid looping…
user11472602
4
votes
4 answers
Function to check if string length in greater than or less than required amount
I want to create a function to check if the length of a string is greater than or less than a required amount:
Something like this:
function check_string_lenght($string, $min, $max)
{
if ($string == "")
{
return x;
}
elseif…
johnathan ross
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4
votes
8 answers
PHP Insert Multiple Spaces
I've got some data that needs to be cleaned up into a fixed length format. I'm using PHP to grab the data out, covert it, and put it back in, but it's not working as planned. There is a certain point in each piece in the middle of the data where…
bmbaeb
- 520
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4
votes
2 answers
What is strlen elision?
I can see it listed as one of the modern C++ idioms, but what it is exactly?
Is it just a type of copy elision?
user5560811
4
votes
7 answers
Usage of fgets function in C
One of my assignments in to write my own UNIX Shell. To receive input from the user, I am using fgets to capture the input as a string but I'm not really sure how it works. When I run:
char command[50];
fgets(command, sizeof(command),…
user446836
- 733
- 4
- 16
- 24
4
votes
2 answers
How does strlen works with numbers?
I am trying to figure out how strlen() finds the length of a number. When I try the following:
echo strlen(00000000000000000000000000000000);
it outputs 1 but when I try
echo strlen(11111111111111111111111111111111111111111111111111111111);
it…
Qeaxe
- 81
- 8
4
votes
3 answers
C char pointer length
This was a quiz (not graded) on Coursera. The question was, what does the following code possibly evaluate to? The correct answers were 127 and 0 (other options were crash, -1, 128. Why does the following code possibly evaluate to 0? I understand…
Nathan Fowler
- 561
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- 19
4
votes
4 answers
string length with fgets function in C
I have a problem. I've tried to see the length of some string after using fgets function. If I enter string under the number of letter which can be in the string (like: the maximum letters in string is 9 and I enter 4 letters), I get length of the…
Raz Omry
- 255
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4
votes
1 answer
Understanding the magic number 0x07EFEFEFF used for strlen optimization
I stumbled upon this answer regarding the utilization of the magic number 0x07EFEFEFF used for strlen's optimization, and here is what the top answer says:
Look at the magic bits. Bits number 16, 24 and 31 are 1. 8th bit is 0.
8th bit represents…
aldeb
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4
votes
4 answers
Is a strlen call in snprintf causing this segfault?
I have a void *, call it data, whose length I know, but is not null terminated. I make a call like this snprintf(line, sizeof(line), "%*s", n, (const char*)data) where n is the known length. Almost always this works, but occasionally it results in…
pythonic metaphor
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4
votes
1 answer
How to determine if a byte is null in a word
I am reading the "strlen" source code from the glibc, and the trick developers found to speed it up is to read n bytes where n is the size of a long word, instead of reading 1 byte at each iteration.
I will assume that a long word has 4 bytes.
The…
Brendan Rius
- 610
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4
votes
4 answers
getting the length of an array using strlen in g++ compiler
could someone explain why i am getting this error when i am compiling the source using following g++ compiler
#include
#include
using namespace std;
int main()
{
char source_language[50];
…
KItis
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- 112
4
votes
3 answers
C Programming - Functionality of strlen
I'm working to try and understand some string functions so I can more effectively use them in later coding projects, so I set up the simple program below:
#include
#include
int main (void)
{
// Declare variables:
char…
Ryan Barker
- 113
- 2
- 11
4
votes
1 answer
string length for mips assembly
Whenever I run the following code:
#counts length of a string
.data
.data
string: .asciiz "Hello"
printedMessage: .asciiz "The length of the string: "
.text
main:
la $a0, string # Load address of string.
jal strlen …
MCsuchNsuch
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