C split a char array into different variables

Question

In C how can I separate a char array by a delimiter? Or is it better to manipulate a string? What are some good C char manipulation functions?

Answer 1

#include<string.h>
#include<stdio.h>
int main()
{
    char input[16] = "abc,d";
    char *p;
    p = strtok(input, ",");

    if(p)
    {
    printf("%s\n", p);
    }
    p = strtok(NULL, ",");

    if(p)
           printf("%s\n", p);
    return 0;
}

you can look this program .First you should use the strtok(input, ",").input is the string you want to spilt.Then you use the strtok(NULL, ","). If the return value is true ,you can print the other group.

Answer 2

Look at strtok(). strtok() is not a re-entrant function.

strtok_r() is the re-entrant version of strtok(). Here's an example program from the manual:

   #include <stdio.h>
   #include <stdlib.h>
   #include <string.h>

   int main(int argc, char *argv[])
   {
       char *str1, *str2, *token, *subtoken;
       char *saveptr1, *saveptr2;
       int j;

       if (argc != 4) {
           fprintf(stderr, "Usage: %s string delim subdelim\n",argv[0]);
           exit(EXIT_FAILURE);
       }

       for (j = 1, str1 = argv[1]; ; j++, str1 = NULL) {
           token = strtok_r(str1, argv[2], &saveptr1);
           if (token == NULL)
               break;
           printf("%d: %s\n", j, token);

           for (str2 = token; ; str2 = NULL) {
               subtoken = strtok_r(str2, argv[3], &saveptr2);
               if (subtoken == NULL)
                   break;
               printf(" --> %s\n", subtoken);
           }
       }

       exit(EXIT_SUCCESS);
   }

Sample run which operates on subtokens which was obtained from the previous token based on a different delimiter:

$ ./a.out hello:word:bye=abc:def:ghi = :

1: hello:word:bye
 --> hello
 --> word
 --> bye
2: abc:def:ghi
 --> abc
 --> def
 --> ghi

Answer 3

One option is strtok

example:

char name[20];
//pretend name is set to the value "My name"

You want to split it at the space between the two words

split=strtok(name," ");

while(split != NULL)
{
    word=split;
    split=strtok(NULL," ");
}

Answer 4

You could simply replace the separator characters by NULL characters, and store the address after the newly created NULL character in a new char* pointer:

char* input = "asdf|qwer"
char* parts[10];
int partcount = 0;

parts[partcount++] = input;

char* ptr = input;
while(*ptr) { //check if the string is over
    if(*ptr == '|') {
        *ptr = 0;
        parts[partcount++] = ptr + 1;
    }
    ptr++;
}

Note that this code will of course not work if the input string contains more than 9 separator characters.

Answer 5

I came up with this.This seems to work best for me.It converts a string of number and splits it into array of integer:

void splitInput(int arr[], int sizeArr, char num[])
{
    for(int i = 0; i < sizeArr; i++)
        // We are subtracting 48 because the numbers in ASCII starts at 48.
        arr[i] = (int)num[i] - 48;
}

Answer 6

This is how I do it.

void SplitBufferToArray(char *buffer, char * delim, char ** Output) {

    int partcount = 0;
    Output[partcount++] = buffer;

    char* ptr = buffer;
    while (ptr != 0) { //check if the string is over
        ptr = strstr(ptr, delim);
        if (ptr != NULL) {
            *ptr = 0;
            Output[partcount++] = ptr + strlen(delim);
            ptr = ptr + strlen(delim);
        }

    }
    Output[partcount++] = NULL;
}

Answer 7

In addition, you can use sscanf for some very simple scenarios, for example when you know exactly how many parts the string has and what it consists of. You can also parse the arguments on the fly. Do not use it for user inputs because the function will not report conversion errors.

Example:

char text[] = "1:22:300:4444:-5";
int i1, i2, i3, i4, i5;
sscanf(text, "%d:%d:%d:%d:%d", &i1, &i2, &i3, &i4, &i5);
printf("%d, %d, %d, %d, %d", i1, i2, i3, i4, i5);

Output:

1, 22, 300, 4444, -5

For anything more advanced, strtok() and strtok_r() are your best options, as mentioned in other answers.

Answer 8

Solution from mic_e was exactly what I was looking for (Thank you) in order to parse Replies from a SIM7600 Module, including the GPS Data from AT+CGNSSINFO. In my first method I created I used strtok which ignored consecutive delimiters. Since the data from AT+CGNSSINFO could have empty fields (i.e. Course) my Routine did not parse all Data correctly. I changed my method according to mic_e's solution and I have now the desired result including empty fields.

char* parts[16];        // change according to total expected fields
char* split2(char* input, char delimiter, int element, int length = 0){
    int partcount = 0;
    parts[partcount++] = input;
    char* ptr = input;
    while (*ptr) { //check if the string is over
        if (*ptr == delimiter) {
            *ptr = 0;
            parts[partcount++] = ptr + 1;
        }
        ptr++;
    }
    if (length != 0) {
        parts[element][length] = '\0';
    }
    return parts[element];
}

// TEST
    char TEST[85] = { "3,04,00,00,ddmm.mmmmmm,N,dddmm.mmmmmm,E,210323,133128.0,999.9,0.0,,14.3,2.2,14.1" };
    for (int i = 0; i < 16; i++)
    {
        //Serial.print(i); Serial.print("\t"); Serial.println(parts[i]);
        Serial.print(i); Serial.print("\t"); Serial.println(split2(TEST,',',i));
    }