hi guys
i hope you can help me...
i am trying to get a list of inputs and put them dynamically (with malloc) in an array. but their sizes and counts are not prdicted.
for ex: a asd dsa g hg .................. ferder ....
i want it to stop when it sees "\n"..
is there anyone to give a example code or a hint..
thanks everyone..
There's various ways.... here's one
- Use a buffer that is long enough to hold all input.
- Once a string is in the buffer, determine it's length
- malloc() memory to hold that many bytes (plus 1 for the null terminator)
- string copy from the buffer to the new memory.
And another:
- malloc() a small amount of memory.
- Load the string from input one char at a time.
- if you run out of room in the malloc()'d memory, just realloc() asking for a few more bytes.
- Continue loading one byte at a time....
Have a go a writing something, then post your code (with code tags) when you have trouble.
When all else fails, read the instructions.
If you're posting code, use code tags: [code] /* insert code here */ [/code]
Do you mean that you read strings of different lengths and want to put them in an array where each array-element contains a string? Then you could use a linked list where each node contains a dynamic character array.
Code:struct node { char *dyn_char_array; struct node *next_node; }
i tried to write that program but got lots of warnings and errors
int main(void)
{
int sum, i;
ip = (void *) malloc(sizeof(input_array));
for(i=0,sum=50 ; (c==getchar()) != '\n' ; i++)
{
if(i > sum) {
ip=(void *) realloc(ip, sizeof(input_array+50));
sum += 50;
}
input_array[i]=c;
}
sum=i;
return 0;
}
i am trying tom put them in an dynamically made array
you wrote:
- malloc() a small amount of memory.
- Load the string from input one char at a time.
- if you run out of room in the malloc()'d memory, just realloc() asking for a few more bytes.
- Continue loading one byte at a time....
i am just trying to do so..
Try this, I think it's fully correct:- malloc() a small amount of memory.
- Load the string from input one char at a time.
- if you run out of room in the malloc()'d memory, just realloc() asking for a few more bytes.
- Continue loading one byte at a time....
Code:#include <stdio.h> #include <stdlib.h> #define INPUT_BLOCK 50 int main(void) { int sum, c; char *ip, *tmp; if ((ip = malloc(INPUT_BLOCK)) == NULL) { perror("malloc"); return (1); } for (sum = 0;(c = getchar()) != '\n'; sum++) { if (sum == INPUT_BLOCK-2) { if ((tmp = realloc(ip, sum + INPUT_BLOCK)) == NULL) { perror ("realloc"); free (ip); return (1); } ip = tmp; } ip[sum] = c; } ip[sum] = '\0'; printf ("Input string is >%s<\n", ip); free (ip); return(0); }
Last edited by Hammer; 05-26-2002 at 12:25 PM.
When all else fails, read the instructions.
If you're posting code, use code tags: [code] /* insert code here */ [/code]
Originally posted by Hammer
- Use a buffer that is long enough to hold all input.
- Once a string is in the buffer, determine it's length
- malloc() memory to hold that many bytes (plus 1 for the null terminator)
- string copy from the buffer to the new memory.
Code:#include <stdio.h> #include <stdlib.h> #include <string.h> #define MAX_LENGTH 50 #define NUMBER_OF_STRINGS 5 int main(void) { char buffer[MAX_LENGTH]; char *ip[NUMBER_OF_STRINGS]; int len, i; for (i = 0; i < NUMBER_OF_STRINGS; i++) { printf ("Enter String number %d: ", i); if (fgets(buffer, MAX_LENGTH, stdin) == NULL) ip[i] = NULL; else { len = strlen(buffer); if (buffer[len-1] == '\n') buffer[len-1] = '\0', len--; if ((ip[i] = malloc(len+1)) == NULL) { perror ("malloc"); return (1); } strcpy (ip[i], buffer); } } for (i = 0; i < NUMBER_OF_STRINGS; i++) { if (ip[i] != NULL) { printf ("String %d is: >%s<\n", i, ip[i]); free(ip[i]); } } return (0); }
When all else fails, read the instructions.
If you're posting code, use code tags: [code] /* insert code here */ [/code]
thank you
