Passing multi-array pointer to function

[drhowarddrfine]

I forgot how to do this. I have a two-dimensional array[i][j] that I initialize a character at a time by looping through j, then increment i, repeat, so i should be an index to the j string. I then want to pass a pointer to this array to another function that can reference the strings by index i, like strcmp("mystrin g",*string[0]); or similar.

I've tried every combination of pointer combination I can think of but it either doesn't work or generates errors. I'm not declaring variables/pointers correctly or I've just blinded myself to a solution.

A little help please.

[JosAH]

I forgot how to do this. I have a two-dimensional array[i][j] that I initialize a character at a time by looping through j, then increment i, repeat, so i should be an index to the j string. I then want to pass a pointer to this array to another function that can reference the strings by index i, like strcmp("mystrin g",*string[0]); or similar.

I've tried every combination of pointer combination I can think of but it either doesn't work or generates errors. I'm not declaring variables/pointers correctly or I've just blinded myself to a solution.

A little help please.

Something like this?

[code=c]
#define NOFSTRINGS 5
#define STRLENGTH 40
...
char strings[NOFSTRINGS][STRLENGTH+1]; // +1 for the terminating '\0'
int i;

// use string[i] here for the i-th string
foo(strings[i]);
...

void foo(char* string) {
// etc.
}
[/code]

kind regards,

Jos

[drhowarddrfine]

I just woke up. I believe that passes one of the strings to the function but I want the function to be able to access each string, individually.

[JosAH]

I just woke up. I believe that passes one of the strings to the function but I want the function to be able to access each string, individually.

use strings[0], strings[1], strings[2] etc.

kind regards,

Jos

[drhowarddrfine]

I thought I tried that already. Here's what I have:

	
char strings[PATH_DEPTH][PATH_NAME_MAX];

foo(page_name[PATH_NAME_MAX]);

void order(char *page_name){
printf("%s",page_name[1]);
}

[JosAH]

I thought I tried that already. Here's what I have:

	
char strings[PATH_DEPTH][PATH_NAME_MAX];

foo(page_name[PATH_NAME_MAX]);

void order(char *page_name){
printf("%s",page_name[1]);
}

I don't know what you're doing there; the individual strings are strings[0] etc.
PATH_NAME_MAX just is the maximum path length (string length) here and
page_name[1] is a single character because page_name (as a parameter in
your 'order' function) happens to be a char* (a pointer to zero or more characters).

kind regards,

Jos

[drhowarddrfine]

Unless I'm misunderstandin g something,

char page_name[PATH_DEPTH][PATH_NAME_MAX];

foo(page_name[i]);

void foo(char *page_name){
printf("%s",page_name);
}

This works and will make foo print the string at page_name[i] of the array, but I want foo to be able to select any of the strings in the array to print without relying on the calling function to pass each string (only a pointer to the whole array).

[JosAH]

Unless I'm misunderstandin g something,

char page_name[PATH_DEPTH][PATH_NAME_MAX];

foo(page_name[i]);

void foo(char *page_name){
printf("%s",page_name);
}

This works and will make foo print the string at page_name[i] of the array, but I want foo to be able to select any of the strings in the array to print without relying on the calling function to pass each string (only a pointer to the whole array).

Ah, ok, you just have to change the type of foo's parameter then:

void foo(char[][PATH_NAME_MAX] page_name, int i) {
   printf("String #%d= %s\n", i, page_name[i]);
}

Note that the column length must be known at compile time.

kind regards,

Jos

[drhowarddrfine]

I think you mean:
void foo(char page_name[][PATH_NAME_MAX] , int i)

That works and I swear I've done that multiple times before but it didn't work. I'm sure I was just messing things up going between two different files and changed something in the process. Thanks.

[JosAH]

I think you mean:
void foo(char page_name[][PATH_NAME_MAX] , int i)

That works and I swear I've done that multiple times before but it didn't work. I'm sure I was just messing things up going between two different files and changed something in the process. Thanks.

Erm, yes, that's what I had in mind but the majority of my mind was still busy
programming in Java, sorry for the incorrect C syntax.

kind regards,

Jos