"const char *foo means it cannot be modified" -> This is not completly correct. 'const char *foo' means foo is a pointer which points to a constant char (pointer to a constant variable, not a constant pointer variable). That means, the address in foo can be changed(foo is not a constant), but we cannot modify the value contained in the address held by foo(the value is considered as constant).
For example
In your code,
you got error in line 6 because, you are trying to change the value contained in the address held by 'dest'. That is if you remove the '*' it wont generate any errors. But the meaning will be different.
you got error in 7 because the dest is a const char * variable. memcpy does not allow const char * as its first argument (memcpy(void *,const void *,size_t))
The work around you are suggesting is similar to what I have given in my previous post. Only difference is you are asking to assign the address of the const char * variable to a char * variable and change the content of the char * variable. I declared the char * variable first and assigned its address to the const char * variable. After that I am also doing the same thing.
I think my previous post created some miss understandings in you. Sorry if it is so.
hello everybody!
I want to create a file with permissions for read, write, and execute to everybody using C, so I write this code:
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
int main(){
int fileDescriptor;
fileDescriptor =... (2 Replies)
Hi,
How to replace any character in a file with a newline character using sed ..
Ex:
To replace ',' with newline
Input:
abcd,efgh,ijkl,mnop
Output:
abcd
efgh
ijkl
mnop
Thnx in advance.
Regards,
Sasidhar (5 Replies)
Hello,
I'm trying to write a method which will return the extension of a file given the file's name, e.g. test.txt should return txt. I'm using C so am limited to char pointers and arrays. Here is the code as I have it:
char* getext(char *file)
{
char *extension;
int i, j;... (5 Replies)
Hi
I m having ifconfig -a o/p like
sbanlab1:ksh# ifconfig -a | egrep "flags|inet" | awk -F' ' '{print $1,$2}'
lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL>
inet 127.0.0.1
lo0:1: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL>
inet 127.0.0.1
bge0:... (1 Reply)
Compiling xpp (The X Printing Panel) on SL6 (RHEL6 essentially):
xpp.cxx: In constructor ‘printFiles::printFiles(int, char**, int&)’:
xpp.cxx:200: error: invalid conversion from ‘const char*’ to ‘char*’
The same error with all c++ constructors - gcc 4.4.4.
If anyone can throw any light on... (8 Replies)
I am writing some code in C++ to print a message using fprintf
Here is an example
void pr_desc(
FILE* stream,
int shift,
const char* desc) {
const char* format="%*s\e;
fprintf(stream,format,shift,"",desc);
}
I call it using
const char* desc;
... (4 Replies)
Dear all,
I am using C and ROOT for programming. And I need to incorporate following in my code.
char *fps=NULL;
int dec=0,sign=0;
float mean = h1->GetMean(1); //0.001298
fps= fcvt(mean,6 , &dec, &sign);
I need to provide this mean as const char to some other function to get... (8 Replies)
Pointers are seeming to get the best of me and I get that error in my program.
Here is the code
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define REPORTHEADING1 " Employee Pay Hours Gross Tax Net\n"
#define REPORTHEADING2 " Name ... (1 Reply)
Discussion started by: Plum
1 Replies
LEARN ABOUT LINUX
string
STRING(3) Linux Programmer's Manual STRING(3)NAME
stpcpy, strcasecmp, strcat, strchr, strcmp, strcoll, strcpy, strcspn, strdup, strfry, strlen, strncat, strncmp, strncpy, strncasecmp, strp-
brk, strrchr, strsep, strspn, strstr, strtok, strxfrm, index, rindex - string operations
SYNOPSIS
#include <strings.h>
int strcasecmp(const char *s1, const char *s2);
int strncasecmp(const char *s1, const char *s2, size_t n);
char *index(const char *s, int c);
char *rindex(const char *s, int c);
#include <string.h>
char *stpcpy(char *dest, const char *src);
char *strcat(char *dest, const char *src);
char *strchr(const char *s, int c);
int strcmp(const char *s1, const char *s2);
int strcoll(const char *s1, const char *s2);
char *strcpy(char *dest, const char *src);
size_t strcspn(const char *s, const char *reject);
char *strdup(const char *s);
char *strfry(char *string);
size_t strlen(const char *s);
char *strncat(char *dest, const char *src, size_t n);
int strncmp(const char *s1, const char *s2, size_t n);
char *strncpy(char *dest, const char *src, size_t n);
char *strpbrk(const char *s, const char *accept);
char *strrchr(const char *s, int c);
char *strsep(char **stringp, const char *delim);
size_t strspn(const char *s, const char *accept);
char *strstr(const char *haystack, const char *needle);
char *strtok(char *s, const char *delim);
size_t strxfrm(char *dest, const char *src, size_t n);
DESCRIPTION
The string functions perform string operations on null-terminated strings. See the individual man pages for descriptions of each function.
SEE ALSO index(3), rindex(3), strcasecmp(3), stpcpy(3), strcat(3), strchr(3), strcmp(3), strcoll(3), strcpy(3), strcspn(3), strdup(3), strfry(3),
strlen(3), strncasecmp(3), strncat(3), strncmp(3), strncpy(3), strpbrk(3), strrchr(3), strsep(3), strspn(3), strstr(3), strtok(3),
strxfrm(3)COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
2010-02-25 STRING(3)