Iterating through a pointer to pointers

Question

If I have char **args how can I loop through the rows of the array to determine how many there are?

For example, if char **args == {"one", "two", "three"}, how can I loop through each element, keeping count, and then return 3?

Answer 1

Since your args is null-terminated, simply write

int i;
for (i = 0; args[i]; i++)
    // do something

Answer 2

You can get the size at compile time as shown below.

This is one way to iterate over the array of strings.

char* args[] = {"one", "two", "three"};

char** p = args;

size_t len = sizeof(args) / sizeof(*args);

for (int i = 0; i < len; ++i) {
    printf("item %u = %s\n", i,  *p++);
}

[EDIT]

I misunderstood, it seems you mean args on the command line (which is null terminated);

In which case you could use:

int main(int argc, char** argv) {
    char** p = argv;
    int count = 0;
    while (*p)
        printf("item %u = %s\n", count++, *p++);
}

or even

int main(int argc, char** argv) {
    int count = 0;
    while (*argv)
        printf("item %u = %s\n", count++, *argv++);
}

Note you will print argv[0] in the above case. Adapt to your needs.

Of course in this case you also have argc so you can iterate until i < argc. Your question is not clear. You should provide full buildable code in your question.

Answer 3

Try the following code:

int count=0;
while(*args++)count++;

printf(" %d\n",count);

while loop should terminate when it reaches the end of the string array, however it would be better to have:

char strAry[M][N]="…your initialization…";
**args;

args=strAry;