Split a string between words and insert newlines - c

Question

i have a string that is made out of a few sentences.
for example:
hello world bye bye
now, i need to make this sentence into a coulmn of words:
hello
world
bye
bye
i have this idea going on, but i dont know how to write it correctly, so i was hopiny ypu guys could help me out.
this is what i have so far:
int len=0, k=0, stopatspace=0;
char temptext[100][15]={0};
char line[300]={0};
len=strlen(line);
printf("len is: %d", len);
for(k=0; k<len; k++)
{
if (k == ' ')
{
// i dont know what to write here in order to make it a cloumn
}
}
basiclly, my idea is to run on all the length of my line and when i reach a space i want it to enter (to go one line down so that it will look like a coulmn)

Answer 1

Suppose line is the char array that contains hello world bye bye and text is declared as
char text[100][15]; //I used 100 and 15 because your example contains it
and you want each word to be copied into each row of text. Then,use strtok() function with " "(space) as delimeter and place this in a loop that terminates when strtok() returns NULL to get each word. Copy each word to each row of text using strcpy() in the loop.
The code for this will look like this:
char text[100][15];
char line[]="hello world bye bye";
int i=0;
char *token=strtok(line," ");
while(token!=NULL)
{
strcpy(text[i],token);
i++;
token=strtok(NULL," ");
}
Now, to print it,you can use
for(int j=0;j<i;j++)
printf("text[%d]=%s",j,text[j]);
Another method would be to manually copy each character until a space is seen.
int len=strlen(line);
int i=0;
int k=0;
for(int j=0;j<len+1;j++)
{
if(line[j]==' ')
{
text[i][k]='\0';
i++;
k=0;
}
else
{
text[i][k]=line[j];
k++;
}
}
Note that the above code does not prevent buffer overflows. You can print each word using
for(int j=0;j<i+1;j++)
printf("text[%d]=%s",j,text[j]);

Answer 2

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char *argv[])
{
char string[100];
fgets(string, 100, stdin);
string[strlen(string)-1] = 0;
// create an array of pointers
char **string_array = (char**)malloc(sizeof(char*));
int i = 0, array_size;
// tokenize input
char *token = strtok(string, " ");
while(token!=NULL) {
// dynamically increase the array during run time
string_array = (char**)realloc(string_array, (i+1)*sizeof(char**));
// create the string as you would do when there is only one string
string_array[i] = (char*)malloc(strlen(token)+1);
strcpy(string_array[i], token);
token = strtok(NULL, " ");
i++;
}
array_size = i;
for(i=0; i<array_size; i++) {
printf("%s\n", string_array[i]);
}
return 0;
}
Basically you create an array of pointers and you allot memory for the strings one by one as you would do when there is only one string.
(if number of token is unknown, use realloc to increase the size of pointer to pointers.)

Answer 3

#include <stdio.h>
#include <ctype.h>
int main(void){
char line[300] = "hello world bye bye\n";
char temptext[100][15]={0};
int i=0, j, k=0;
while(line[k]){
if(isspace(line[k])){
++k;//skip space to word
continue;
}
for(j=0; j < 15-1 && line[k] && !isspace(line[k]); ++k, ++j)
temptext[i][j] = line[k];
if(j && ++i == 100)
break;
}
for(j=0; j<i; ++j)
puts(temptext[j]);
return 0;
}

Answer 4

#include<stdio.h>
#define NEWLINE printf("\n")
int main(void)
{
char string[]="hello world bye bye";
int index=0;
while(string[index])
{
if(string[index]==32)
{
NEWLINE;
index++;
}
else
{
printf("%c",string[index]);
index++;
}
}
NEWLINE;
}
// Whenever i encountered with a space, i am printing a new line on the screen. Here 32 is the ASCII value for space