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Q&A 2D-array pointer as a struct member

I have an array of struct: static struct basket baskets[MAX_ITEMLEN + 1]; struct basket { char *items; // malloc(itemlen * itemcount) int itemcount; }; char *items does all I nee...

2 answers · posted 2d ago by wasIzy‭ · last activity 7h ago by Alexei‭

Question c array

#3: Post edited by

wasIzy‭ · 2025-01-08T23:31:16Z (about 18 hours ago)

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I have an array of struct:
```
static struct basket baskets[MAX_ITEMLEN + 1];
struct basket {
char *items; // malloc(itemlen * itemcount)
int itemcount;
};
```
`char *items` does all I need to do with some pointer-gymnastics, but at times it gets a little ugly.
I would prefer a 2D-array pointer allowing `items[item_index][char_index]` navigation by default, but all my attempts to get a 2D-array pointer as struct member have failed miserably.
If it is indeed possible: how?
### Details (in case relevant):
#1 Specs:
```c
#define MAX_ITEMLEN 20
#define MAX_ITEMCOUNT 16000
```
~~#2 `itemcount(s)` & `item-chars` are not known at compile-time but are derived at start-up by parsing two user-provided .txt files~~
#3 The code will not interrogate `baskets[x]` having `itemcount == 0`
#4 `*items` is initialised: |←item_chars→|←item_chars→| ...itemcount times
...with no delimiters ('\0' or otherwise)
#5 After initialsation, `basket[]` is invariant until `exit()`

I have an array of struct:
```
static struct basket baskets[MAX_ITEMLEN + 1];
struct basket {
char *items; // malloc(itemlen * itemcount)
int itemcount;
};
```
`char *items` does all I need to do with some pointer-gymnastics, but at times it gets a little ugly.
I would prefer a 2D-array pointer allowing `items[item_index][char_index]` navigation by default, but all my attempts to get a 2D-array pointer as struct member have failed miserably.
If it is indeed possible: how?
### Details (in case relevant):
#1 Specs:
```c
#define MAX_ITEMLEN 20
#define MAX_ITEMCOUNT 16000
```
#2 `itemcount`(s) & the char content of each item are not known at compile-time but are derived at start-up by parsing two user-provided .txt files
#3 The code will not interrogate `baskets[x]` having `itemcount == 0`
#4 `*items` is initialised: |←item_chars→|←item_chars→| ...itemcount times
...with no delimiters ('\0' or otherwise)
#5 After initialsation, `basket[]` is invariant until `exit()`

#2: Post edited by

Alexei‭ · 2025-01-08T08:23:06Z (1 day ago)
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I have an array of struct:
```
static struct basket baskets[MAX_ITEMLEN + 1];
struct basket {
char *items; // malloc(itemlen * itemcount)
int itemcount;
};
```
`char *items` does all I need to do with some pointer-gymnastics, but at times it gets a little ugly.
I would prefer a 2D-array pointer allowing `items[item_index][char_index]` navigation by default, but all my attempts to get a 2D-array pointer as struct member have failed miserably.
If it is indeed possible: how?
~~wasizy~~
~~Details (in case relevant):~~
~~#1 Specs: #define MAX_ITEMLEN 20 #define MAX_ITEMCOUNT 16000~~
~~#2 itemcount(s) & item-chars are not known at compile-time, but are derived at start-up by parsing two user-provided .txt files~~
~~#3 The code will not interrogate baskets[x] having itemcount == 0~~
~~#4 *items is initialised: |←item_chars→|←item_chars→| ...itemcount times~~
...with no delimiters ('\0' or otherwise)
~~#5 After initialsation, basket[] is invariant until exit()~~

I have an array of struct:
```
static struct basket baskets[MAX_ITEMLEN + 1];
struct basket {
char *items; // malloc(itemlen * itemcount)
int itemcount;
};
```
`char *items` does all I need to do with some pointer-gymnastics, but at times it gets a little ugly.
I would prefer a 2D-array pointer allowing `items[item_index][char_index]` navigation by default, but all my attempts to get a 2D-array pointer as struct member have failed miserably.
If it is indeed possible: how?
### Details (in case relevant):
#1 Specs:
```c
#define MAX_ITEMLEN 20
#define MAX_ITEMCOUNT 16000
```
#2 `itemcount(s)` & `item-chars` are not known at compile-time but are derived at start-up by parsing two user-provided .txt files
#3 The code will not interrogate `baskets[x]` having `itemcount == 0`
#4 `*items` is initialised: |←item_chars→|←item_chars→| ...itemcount times
...with no delimiters ('\0' or otherwise)
#5 After initialsation, `basket[]` is invariant until `exit()`

c array

#1: Initial revision by

wasIzy‭ · 2025-01-07T22:20:12Z (2 days ago)

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2D-array pointer as a struct member

I have an array of struct:
```
static struct basket baskets[MAX_ITEMLEN + 1];

struct basket {
  char *items;      // malloc(itemlen * itemcount)
  int itemcount;
};
```

`char *items` does all I need to do with some pointer-gymnastics, but at times it gets a little ugly.

I would prefer a 2D-array pointer allowing `items[item_index][char_index]` navigation by default, but all my attempts to get a 2D-array pointer as struct member have failed miserably.

If it is indeed possible: how?

wasizy




Details (in case relevant):

#1 Specs:  #define MAX_ITEMLEN 20  #define MAX_ITEMCOUNT 16000

#2 itemcount(s) & item-chars are not known at compile-time, but are derived at start-up by parsing two user-provided .txt files

#3 The code will not interrogate baskets[x] having itemcount == 0

#4 *items is initialised: |←item_chars→|←item_chars→| ...itemcount times
    ...with no delimiters ('\0' or otherwise)

#5 After initialsation, basket[] is invariant until exit()

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