How to split a string and new line using strtok

Question

I am trying to split my string and the (\n)new line and want to get the new string without \n.My code is as below.Thanks.

token = strtok(NULL,"")

The above snippet will store "some string and \n" where as I need just "some string".

My data looks like this.

1,v1,p1,182,1665,unkn

Use std::string and the algorithms to do it in C++. Much safer. — DumbCoder, Nov 16 '12 at 12:43
You should look into http://stackoverflow.com/questions/236129/splitting-a-string-in-c to see how to do this in C++. — Björn Pollex, Nov 16 '12 at 12:46
@SOaddict You have done a `strtok(your_string, separators);` before that? The `NULL` as first argument is for calls to `strtok` after the first. And you must of course check whether `token` is `NULL`, at which point you've reached the end of the input string. — Daniel Fischer, Nov 16 '12 at 12:49
Yes I am at the end of my input string.My data looks like this "1,v1,p1,182,1665,unkn".I am trying to extract "unkn" from this input. — Teja, Nov 16 '12 at 12:52

AndersK · Accepted Answer · 2012-11-17T16:43:48.157

3

If you data looks like this

char line[] = "1,v1,p1,182,1665,unkn\n";

you could do something like this (in C)

char* p = line + strlen(line) - 1;
for (;*p != ','; --p) 
{
  ;
}
char* lastword = strtok(p + 1,"\n");

edited Nov 17 '12 at 16:43

answered Nov 16 '12 at 13:26

AndersK

That's valid C99, but many compilers will prefer the `lastword` declared at the top (but still assigned at the bottom, of course). – ams Nov 16 '12 at 13:30
And it would be better to use a standard function like `strrchr` to find the last comma. – ams Nov 16 '12 at 13:33

score 0 · Answer 2 · edited Nov 16 '12 at 13:47

0

If all you are doing is replacing the first newline then this is much better:

char *tmp = strchr (str, '\n');
if (tmp) *tmp = 0;

If you are replacing the last newline in the string then this is better:

char *tmp = strrchr (str, '\n');
if (tmp) *tmp = 0;

edited Nov 16 '12 at 13:47

Patrick Schlüter

answered Nov 16 '12 at 13:34

Lelanthran

2 Answers2