strtok

I am trying to tokenize a string but I need to know exactly when no data is seen between two tokens. e.g when tokenizing the following string " a,b,c,,,d,e " I need to know about the two empty slots between ' d ' and ' e '... which I am unable to find out simply using strtok() . My attempt is shown below: char arr_fields[num_of_fields]; char delim[]=",\n"; char *tok; tok=strtok(line,delim);//line contains the data for(i=0;i<num_of_fields;i++,tok=strtok(NULL,delim)) { if(tok) sprintf(arr_fields[i], "%s", tok); else sprintf(arr_fields[i], "%s", "-"); } Executing the above code with the

I was wondering how you could take 1 string, split it into 2 with a delimiter, such as space, and assign the 2 parts to 2 separate strings. I've tried using strtok() but to no avail. ereOn #include <string.h> char *token; char line[] = "SEVERAL WORDS"; char *search = " "; // Token will point to "SEVERAL". token = strtok(line, search); // Token will point to "WORDS". token = strtok(NULL, search); Update Note that on some operating systems, strtok man page mentions: This interface is obsoleted by strsep(3). An example with strsep is shown below: char* token; char* string; char* tofree; string =

Could someone explain me what differences there are between strtok() and strsep() ? What are the advantages and disadvantages of them? And why would I pick one over the other one. George Gaál From The GNU C Library manual - Finding Tokens in a String : One difference between strsep and strtok_r is that if the input string contains more than one character from delimiter in a row strsep returns an empty string for each pair of characters from delimiter. This means that a program normally should test for strsep returning an empty string before processing it. One major difference between strtok()

I am trying to understand why the following snippet of code is giving a segmentation fault: void tokenize(char* line) { char* cmd = strtok(line," "); while (cmd != NULL) { printf ("%s\n",cmd); cmd = strtok(NULL, " "); } } int main(void) { tokenize("this is a test"); } I know that strtok() does not actually tokenize on string literals, but in this case, line points directly to the string "this is a test" which is internally an array of char . Is there any of tokenizing line without copying it into an array? The problem is that you're attempting to modify a string literal. Doing so causes your

I need to use strtok to read in a first and last name and seperate it. How can I store the names where I can use them idependently in two seperate char arrays? #include <stdio.h> #include <string.h> int main () { char str[] ="test string."; char * test; test = strtok (str," "); while (test != NULL) { printf ("%s\n",test); test= strtok (NULL, " "); } return 0; } Here is my take at a reasonably simple tokenize helper that stores results in a dynamically growing array null-terminating the array keeps the input string safe (strtok modifies the input string, which is undefined behaviour on a

I am trying to use strtok() in nested loop. But this is not giving me desired results. Possibly because they are using same memory location. My code is of the form:- char *token1 = strtok(Str1, "%"); while(token1 != NULL ) { char *token2 = strtok(Str2, "%"); while(token2 != NULL ) { //DO SMTHING token2 = strtok(NULL, "%"); } token1 = strtok(NULL, "%"); // Do something more } Yes, strtok() , indeed, uses some static memory to save its context between invocations. Use a reentrant version of strtok() , strtok_r() instead, or strtok_s() if you are using VS (identical to strtok_r() ). It has an

What feature(s) of strtok is unsafe (in terms of buffer overflow) that I need to watch out for? What's a little weird to me is that strtok_s (which is "safe") in Visual C++ has an extra "context" parameter, but it looks like it's the same in other ways... is it the same, or is it actually different? According with the strtok_s section of this document : 6.7.3.1 The strtok_s function The strtok_s function fixes two problems in the strtok function: A new parameter, s1max, prevents strtok_s from storing outside of the string being tokenized. (The string being divided into tokens is both an input

This question already has an answer here: Using strtok() in a loop in C? 3 answers I have a string like this: a;b;c;d;e f;g;h;i;j 1;2;3;4;5 and i want to parse it element by element. I used nested strtok function but it just splits first line and makes null the token pointer. How can i overcome this? Here is the code: token = strtok(str, "\n"); while(token != NULL && *token != EOF) { char a[128], b[128]; strcpy(a,token); strcpy(b,a); printf("a:%s\n",a); char *token2 = strtok(a,";"); while(token2 != NULL) { printf("token2 %s\n",token2); token2 = strtok(NULL,";"); } strcpy(token,b); token =