|
|
Sponsored Content
Top Forums
Programming
pointer arithmetic vs. strlen() & strnlen()?
Post 302280375 by shamrock on Monday 26th of January 2009 06:09:46 PM
01-26-2009
Quote:
I have been getting some flack recently for my use of strlen() and strnlen(). Honestly I have always just taken their functionality for granted as being the easiest way of getting the length of a string. Is it really so much better to do pointer arithmetic? What am I gaining besides more thought-process for me to worry about?
do you work in embedded systems??? strlen and strnlen are library functions so there is overhead associated with them but that is normal. The alternative is to roll your own using pointers but that as you rightly said is just more thought-process. That is why I am wondering if you are working in embedded systems?|
|
10 More Discussions You Might Find Interesting
1. Programming
hello,
i have a problem with strlen. I have written this:
for(y=13,z=0; cInBuf!=' ';y++)
{
cBuf=cInBuf;
z++;
}
len = strlen(cBuf);
out=len/2;
fprintf(outfile,"F%i",out);
If strlen is e.g. 22, it write F22. I want to write F2F2.
How can i do this?... (5 Replies)
Discussion started by: ACeD
5 Replies
2. Shell Programming and Scripting
Hello,
Just a little problem with the ksh function : strlen
I want to use this function in this little ksh program :
while read line ; do
TOTO=$line
TOTONB=strlen($TOTO)
echo $TOTONB (3 Replies)
Discussion started by: steiner
3 Replies
3. Programming
In a declaration, I have:
const char comment_begin = "<!--";
const char comment_end = "-->";
const int comment_begin_len = strlen(comment_begin);
const int comment_end_len = strlen(comment_end);
When I compile, I get the warnings:
emhttpc.c:64: warning: initializer element is not... (10 Replies)
Discussion started by: cleopard
10 Replies
4. Programming
If one wants to get a start address of a array or a string or a block of memory via a function, there are at least two methods to achieve it:
(1) one is to pass a pointer-to-pointer parameter, like:
int my_malloc(int size, char **pmem)
{
*pmem=(char *)malloc(size);
if(*pmem==NULL)... (11 Replies)
Discussion started by: aaronwong
11 Replies
5. Shell Programming and Scripting
Hi, I hope the title does not scare people to look into this thread but it describes roughly what I'm trying to do. I need a solution in PHP.
I'm a programming beginner, so it might be that the approach to solve this, might be easier to solve with an other approach of someone else, so if you... (0 Replies)
Discussion started by: lowmaster
0 Replies
6. Programming
My OS (Debian) and gcc use the UTF-8 locale. This code says that the char size is 1 byte but the size of 'a' is really 4 bytes.
int main(void)
{
setlocale(LC_ALL, "en_US.UTF-8");
printf("Char size: %i\nSize of char 'a': %i\nSize of Euro sign '€': %i\nLength of Euro sign: %i\n",... (8 Replies)
Discussion started by: cyler
8 Replies
7. Programming
I have a fundamental question on C pointer arithmetry..
Suppose i have a c string pointer already pointing to a valid location, Can I just do a
charptr = charptr +1;
to get to the next location, irregardless if my program is 32 or 64 bits?
or should i do it this way:
charptr =... (1 Reply)
Discussion started by: Leion
1 Replies
8. Programming
When i want to use a list of strings
char *list; i never understand it well.
Here is an easy example. It took me long to figure it out, searching the web didn't help much:
#include <stdio.h>
int main(void)
{
char *list = {"foo", "bar", "baz"};
char **pl;
int... (6 Replies)
Discussion started by: tornow
6 Replies
9. Programming
Hello,
This function was copied into my code, which was compiled without error/warning, but when executed there is always Segmentation fault at the end after the output (which seems correct!):
void get_hashes(unsigned int hash, unsigned char *in)
{
unsigned char *str = in;
int pos =... (7 Replies)
Discussion started by: yifangt
7 Replies
10. Shell Programming and Scripting
greetings,
pretty new to php and i think i might be missing some fundamental limitation of isset. i have two php scripts below that are executed by crond, one using --host X and one that does not. and below that are three different attempts at generating a command line that will be executed. the... (8 Replies)
Discussion started by: crimso
8 Replies
LEARN ABOUT X11R4
strnlen
STRNLEN(3) Linux Programmer's Manual STRNLEN(3) NAME
strnlen - determine the length of a fixed-size string SYNOPSIS
#include <string.h> size_t strnlen(const char *s, size_t maxlen); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): strnlen(): Since glibc 2.10: _POSIX_C_SOURCE >= 200809L Before glibc 2.10: _GNU_SOURCE DESCRIPTION
The strnlen() function returns the number of characters in the string pointed to by s, excluding the terminating null byte (' '), but at most maxlen. In doing this, strnlen() looks only at the first maxlen characters in the string pointed to by s and never beyond s+maxlen. RETURN VALUE
The strnlen() function returns strlen(s), if that is less than maxlen, or maxlen if there is no null terminating (' ') among the first maxlen characters pointed to by s. ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7). +----------+---------------+---------+ |Interface | Attribute | Value | +----------+---------------+---------+ |strnlen() | Thread safety | MT-Safe | +----------+---------------+---------+ CONFORMING TO
POSIX.1-2008. SEE ALSO
strlen(3) COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/. GNU
2016-03-15 STRNLEN(3)