C char[] single character removal *SOLVED*

[Troy Martin]

Okay, I have a char array that I have the location of two characters that I need to remove. I tried setting them to '\0' but that didn't work. What can I do? The locations in the string are strlen(input)-6 and strlen(input)-5.

Background information: I'm implementing a line-by-line C cross-compiler for an OS (I don't think I should mention the name) and I'm using this to implement a final "\n" in puts().

[Alboin]

Why not just copy the string over itself, thus overwriting the unwanted parts?

Note: '\0' indicates the end of the string. Overwriting a character with it would just prematurely end the string.

[AndrewAPrice]

Out of curiosity, why are you modifying the string?
I read the source in from a stream byte-by-byte using an iterator, and if I wanted to skip over a character I just increased the iterator.

[DeletedAccount]

Man , use a debugger and find out what exactly is going on ... , set breakpoints etc ...

Regards
Sandeep

[AJ]

Man , use a debugger and find out what exactly is going on ... , set breakpoints etc ...

Agree with the debugger bit (a memory dump may have helped the OP although given the original question that may be assuming too much), but out of interest where would it help to put a breakpoint to help with this query? The OP already knows that things go wrong after replacing the characters with '\0'.

Cheers,
Adam

[DeletedAccount]

Hi ,
I really not know where exactly . But i might set it where the function gets called . Also i do not have any details here .
Regards
Sandeep

[B.E]

I hope your checking input to make sure it's length is 6+ because 5-6=-1 and 5-5 = 0, ie buffer overflow.

if you have not solve this problem yet. give you a clue.

Code: Select all

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define STR "1234567890"

char * getstring(char * input){
	char *i, *j;
	int inputlen, k=0;

	i = j = input;
	inputlen = strlen(input);

	for(;*i;k++){
		*i = *j++;
		if ((k == inputlen-6) || (k == inputlen-5))
			continue;
		i++;
	}
	return input;
}

int main(){
	char *tmp = malloc(strlen(STR)+1);
	strcpy(tmp, STR);
	printf("%s\n", getstring(tmp));
        return 0;
}

NOTE if code looks like crap, it's because I haven't programmed in c for a while.