How do I store a pointer into my 2d array?

Question

I am suppose to store the pointer to a command into a 2d array. Below is a little bit of code that I am using, but I dont know how to get the desired result.

#define MAX_LINE_LENGTH 1024
#define MAX_COMMANDS 10
char *commandHistory[MAX_COMMANDS][MAX_LINE_LENGTH + 1];


char *token;
token = strtok(line, LSH_TOK_DELIM);
printf("%s\n", token); //prints out the command I want to store the pointer to
commandHistory[i++][0] = token; //what do I do here?

Why do you split line ? just do `commandHistory[i++] = strdup(line);` — Ôrel, Apr 07 '15 at 01:03

score 0 · Answer 1 · answered Apr 07 '15 at 01:05

0

You need to allocate a copy of the string and store that. The simplest way to do that is like this:

commandHistory[i++][0] = strdup(token);

When your program is finished with these, you should free each one that is allocated using strdup.

answered Apr 07 '15 at 01:05

Edward

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Lets say commandHistory[0][0] = ls. I have another token thats a string that I need to add onto commandHistory[0][0]. How would I do this? – connor moore Apr 07 '15 at 01:18
That would be [a different question](http://stackoverflow.com/questions/10279718/append-char-to-string-in-c). – Edward Apr 07 '15 at 01:21

score 0 · Answer 2 · edited Apr 07 '15 at 01:35

You also need not to set second dimension. Declare it like this.

char *commandHistory[MAX_COMMANDS]={};

This is an array of pointers. You can enforce the MAX_LINE_LENGTH of the string read from input source and as others mentioned store the newly allocated string in the location like:

commandHistory[i++]= strdup(token);

If you want to go with 2 dimensional array then you need to copy the token into the array like:

char commandHistory[MAX_COMMANDS][MAX_LINE_LENGTH + 1] ={};
strcpy_s(commandHistory[i++], MAX_LINE_LENGTH+1, token);

How do I store a pointer into my 2d array?

2 Answers2