Convert string to int in c

Question

What I am trying to do is to access a string value in a multidimensional string array in C. The string is actually a number value which I want to store in an integer value.

When I try to print the value as following

  printf("TESTING COMMAND\n");
  printf("%d\n",commands[0][0]);

The value prints the normal expected value

However when I try to use it to initialize an array for example as below

  char **options[ (x - 1) ];

This gives the following error

  error: size of array ‘options’ has non-integer type

Which I expect because the command array is declared as following

  char ***commands;

The thing is that even if I try to assign an integer variable to hold this value I get a segmentation error

 x = command[0][0];

I have also tried functions like strtol which led to the same result. However I am not sure if I have used the function right.

Any suggestions ?

int x;
printf("TESTING COMMAND\n");
printf("%d\n",commands[0][0]);
x = command[0][0];
printf("Creating options of size = %d\n", x );

`printf("%d\n",commands[0][0]);` What is command, how is it defined/declared? — wildplasser, Apr 03 '15 at 22:51
@mcleod_ideafix that is the code where I try to assign the integer to a variable int x; printf("TESTING COMMAND\n"); printf("%d\n",commands[0][0]); x = command[0][0]; printf("Creating options of size = %d\n", x ); — Abdelrahman Shoman, Apr 03 '15 at 23:09
@Abdel-RahmanShoman Is there any good reason to present the code in reversed order? I like to read top to bottom. (and so does my compiler) — wildplasser, Apr 03 '15 at 23:11

score 0 · Answer 1 · 2019-11-11T15:33:00.417

0

Try the sscanf formatting function.

It works like - void sscanf(char *arr, "format-specifier", address of var to store the formatted value.)

For eg : say we have - char *arr = "123" declare int val;

then- sscanf(arr, "%d", &val); val will equal 123.

edited Nov 11 '19 at 15:33

answered Oct 26 '19 at 05:55

Could you please format your answer a bit better to make it more readable? Thank you – slfan Oct 26 '19 at 06:16

score -1 · Answer 2 · answered Apr 04 '15 at 00:22

-1

The function you're looking for is probably atoi():

x = atoi(commands[0][0]);

It parses the string as a number and returns it as an int. You'll need to include stdlib.h.

answered Apr 04 '15 at 00:22

Dolda2000

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since `atoi()` has no way of reporting errors, and it invokes undefined behavior upon overflow, its use is discouraged – please do **not** recommend it. A more modern alternative is `strtol()`. – The Paramagnetic Croissant Apr 04 '15 at 00:46
1

In the vast majority of situations there isn't much reason to care about those shortcomings, however, and it *is* simpler to use. :) – Dolda2000 Apr 04 '15 at 00:47
2

carelessly ignoring error conditions is unprofessional because it is dangerous. Do not encourage doing it! – The Paramagnetic Croissant Apr 04 '15 at 07:42
It's not like it causes security problems, crashing or other reliability issues. It is not necessarily meaningful to report every user mistake in every piece of software. – Dolda2000 Apr 04 '15 at 14:24

Convert string to int in c

2 Answers2