how to get substring from a bigger string in c?

Question

when in java we can use

sting_name.substring(start, end);

to get a new substring

    String full_line = "this is a simple line.";
    String part_line;
    System.out.println(full_line);
    part_line = full_line.substring(10, 16);
    System.out.println(part_line);

how can do that same thing in c? is there any function similar to substring?

char full_line[] = "this is a simple line" ;
char part_line[20];
printf("\n%s\n",full_line);
//part_line ;

Pointer arithmetic and `memcpy()`. [Example](https://github.com/H2CO3/Sparkling/blob/master/src/rtlb.c#L660-694). — , Jan 22 '14 at 19:50

score 0 · Answer 1 · answered Jan 22 '14 at 19:52

0

Use strncpy

Example

#include <stdio.h>
#include <string.h>

int main()
{
   char src[40];
   char dest[12];

   memset(dest, '\0', sizeof(dest));
   strcpy(src, "This is tutorialspoint.com");
   strncpy(dest, src+2, 10);

   printf("Final copied string : %s\n", dest);

   return(0);
}

answered Jan 22 '14 at 19:52

ProfessionalAmateur

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Why is everyone casting the return value of `malloc()`...!? – Jan 22 '14 at 19:53
1

This answer is *very* wrong. (in fact: almost every use of strncpy() is wrong) – wildplasser Jan 22 '14 at 19:54
@H2CO3 - it was just the first example I grabbed. I changed it to a more straight forward example – ProfessionalAmateur Jan 22 '14 at 19:55
also, was the original version plagiarized from the other answer or vice versa? They had the same content up until very recently. – Jan 22 '14 at 19:55
@H2CO3 - Yes I googled it, didnt write it myself. I thought this question was going to be closed quickly so I wanted to give the OP an answer he could use before it did. – ProfessionalAmateur Jan 22 '14 at 19:56
In the new version you manage to perform *three* passes over the string just to copy (part of) it. – wildplasser Jan 22 '14 at 19:57
@wildplasser - Feel free to edit it. The answer to his question is `strncpy` I just tried to provide a little context before the question is closed. – ProfessionalAmateur Jan 22 '14 at 19:59
I don't edit other peoples submissions. But I strongly object to any usage of strncpy(). – wildplasser Jan 22 '14 at 20:02
1

@wildplasser - Post your solution as an answer. More than 1 way to skin a cat. – ProfessionalAmateur Jan 22 '14 at 20:03

score 0 · Accepted Answer · edited May 23 '17 at 12:03

0

Get a substring of a char*

after looking at above link I tried this: just want to make sure if this is correct way of doing this or there is downside of this?

char full_line[] = "this is a simple line" ;
char part_line[20];
printf("\n%s\n",full_line);
memcpy( part_line, &full_line[10], 6);
part_line[6+1] = '\0';
printf("\n%s\n",part_line);

edited May 23 '17 at 12:03

Community

1
1

answered Jan 22 '14 at 20:03

Deepak

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how to get substring from a bigger string in c?

2 Answers2