I was having some difficulties when trying to print out the string pointer after dynamically insert a character at the front of char array.
The parameter *str is a dynamic char array from my main whereas the input is a single character which should append to the first element of the dynamic array after executing the insert().
int main(){
//code snippet. I removed other part to keep the question short
printf("How many characters do you want to input: ");
scanf("%d", &n);
str = malloc(n + 1);
printf("Input the string class: ");
scanf("%s", str);
//switch statement
case '1':
printf("What is the character you want to insert: ");
scanf(" %c", &input);
insert(&str, input);
break;
}
return 0;
}
void insert(char *str, char input) {
char *new_str;
int i, len = strlen(str);
new_str = malloc(len + 1);
new_str[0] = input;
strncpy(&new_str[1], str, len - 1);
new_str[len] = 0;
for (i = 0; i < len; i++) {
printf("%c", new_str[i]);
}
}
When I tried to loop thru the new_str and print out the string array, it gives me weird symbols and I have no idea what are they. Any ideas?
EDIT
The expected output as below:
How many characters do you want to input: 5
Input the string:datas
The string is: datas
Do you want to 1-insert or 2-remove or 3-quit?: 1
What is the character you want to insert: a
Resulting string: adata
The output I am getting:
Alternative version, avoiding any string copy functions. (Since, alter the strlen() you already know the string length to copy, you don't need any more string functions)
char * insert_a_character(char * str, char ch)
{
char * new;
size_t len;
if (!str) return NULL;
len = strlen(str);
new = malloc (1+len+1);
if (!new) retun NULL;
new[0] = ch;
memcpy(new+1, str, len);
new[len+1] = 0;
return new;
}
I assume that the caller will free if required for orig
char * insert(char *orig, char input) {
char * new_str = malloc(strlen(orig) + 2); // An extra one for null
strcpy(new_str + 1, orig);
new_str[0] = input;
printf("%s", new_str); // To print it out
return new_str; // The caller needs to free this;
}
That should work.
Assembling all comments:
void insert(char *str, char input) {
char *new_str;
int i, len = strlen(str);
new_str = malloc(len + 2);
new_str[0] = input;
strcpy(new_str+1, str);
new_str[len+1] = 0;
for (i = 0; i <= len; i++) {
printf("%c", new_str[i]);
}
}
Of course you still need to do something with the new string, such as returning it or freeing it.
Related
I am writing some C Code where the user enters the desired string size and then a string which will be reversed then printed (as opposed to being printed in reverse.) I also would like to mention that I don't want to use external libraries, the whole point of this is to be able to do it manually. I used dynamic memory allocation to create a string of a size inputted by the user and called a "Reverse Array" function. Everything works fine until the function is called. My method for reversing the string followed the same principle as reversing a normal array but instead of moving integers around I moved characters around. Can you explain to me what I have done wrong?
My Code:
#include <stdio.h>
#include <stdlib.h>
int RvsArr(char *Str, int end)
{
int start = 0;
char tmp;
while (start < end)
{
tmp = Str[start];
Str[start] = Str[end];
Str[end] = tmp;
start++;
end--;
}
printf("%s", Str);
return 0;
}
int main()
{
int ArrSz;
printf("Please enter array size: ");
scanf("%i", &ArrSz);
char *Str;
Str = (char *)malloc(ArrSz * sizeof(char));
printf("Please enter your string: ");
scanf("%s", Str);
RvsArr(Str, ArrSz);
free(Str);
return 0;
}
You need to reverse the actual string, not the full buffer.
char *RvsArr(char* Str)
{
char *end, *wrk = Str;
char tmp;
if(wrk && *wrk)
{
end = Str + strlen(wrk) - 1;
while(wrk < end)
{
tmp = *wrk;
*wrk++ = *end;
*end-- = tmp;
}
}
return Str;
}
int main()
{
int ArrSz;
printf("Please enter array size: ");
scanf(" %i", &ArrSz);
char* Str;
Str = malloc(ArrSz * sizeof(char));
printf("Please enter your string: ");
scanf(" %s", Str);
printf("\n`%s`\n", RvsArr(Str));
free(Str);
return 0;
}
https://godbolt.org/z/azob5s
For starters the user can enter a string the size of which can be less than the size of the dynamically allocated character array that stores the string.
So passing the size of the array does not make a sense. The size of the array is not the same as the size of the entered string.
Also this expression Str[end] access memory beyond the allocated array in the first iteration of the while loop.
And the return type int also does not make a sense.
Apart from this the function should not output anything. It is the caller of the function that will decide to output the result string or not.
Pay attention to that this call
scanf("%s", Str);
is unsafe. It would be better to use the function fgets. For example
fgets( Str, ArrSz, stdin );
In this case you will need to remove the new line character '\n' that the function can append to the entered string.
Without using standard string functions the function can be defined the following way as it is shown in the demonstrative program below.
Instead of the senseless return type int the function returns a pointer to the first character of the reversed string.
#include <stdio.h>
char * RvsArr( char *s )
{
char *last = s;
while ( *last ) ++last;
if ( last != s )
{
for ( char *first = s; first < --last; ++first )
{
char c = *first;
*first = *last;
*last = c;
}
}
return s;
}
int main(void)
{
char s[] = "Hello World!";
puts( s );
puts( RvsArr( s ) );
return 0;
}
The program output is
Hello World!
!dlroW olleH
If you are allowed to use standard string functions then the function RvsArr can look the following way (provided that the header <string.h> is included)
char * RvsArr( char *s )
{
char *last = s + strlen( s );
if ( last != s )
{
for ( char *first = s; first < --last; ++first )
{
char c = *first;
*first = *last;
*last = c;
}
}
return s;
}
Character arrays or string in c(as it is generally referred to) requires one extra byte which store null character ('\o' or 0) to indicate the end of string. You can store ArrSz - 1 character in your array and ArrSz byte stores the termination character('\o' or 0).
int RvsArr(char* Str, int end)
{
if (Str == 0 || end <= 1)
return 0;
int start = 0;
char tmp;
while(start < end)
{
tmp = Str[start];
Str[start] = Str[--end]; // pre decrement the counter to last char
Str[end] = tmp;
start++;
}
printf("%s", Str);
return 0;
}
or in other version
int RvsArr(char* Str, int end)
{
if (Str == 0 || end <= 1)
return 0;
int start = 0;
int last = end - 1;
char tmp;
while(start < last)
{
tmp = Str[start];
Str[start] = Str[last];
Str[last] = tmp;
start++;
last--;
}
printf("%s", Str);
return 0;
}
And some changes in main function are
int main()
{
int ArrSz;
printf("Please enter array size: ");
scanf("%i", &ArrSz);
char *Str;
Str = (char *)malloc(ArrSz * sizeof(char));
printf("Please enter your string: ");
scanf("%s", Str);
Str[ArrSz] = '\0'; // Here we have no control on how many characters are read, scan is a security vulnerability becuse of this
printf("Input=%s, len=%d\n", Str, strlen(Str));
RvsArr(Str, strlen(Str));
free(Str);
return 0;
}
I want to write a program in C that displays each word of a whole sentence (taken as input) at a seperate line. This is what I have done so far:
void manipulate(char *buffer);
int get_words(char *buffer);
int main(){
char buff[100];
printf("sizeof %d\nstrlen %d\n", sizeof(buff), strlen(buff)); // Debugging reasons
bzero(buff, sizeof(buff));
printf("Give me the text:\n");
fgets(buff, sizeof(buff), stdin);
manipulate(buff);
return 0;
}
int get_words(char *buffer){ // Function that gets the word count, by counting the spaces.
int count;
int wordcount = 0;
char ch;
for (count = 0; count < strlen(buffer); count ++){
ch = buffer[count];
if((isblank(ch)) || (buffer[count] == '\0')){ // if the character is blank, or null byte add 1 to the wordcounter
wordcount += 1;
}
}
printf("%d\n\n", wordcount);
return wordcount;
}
void manipulate(char *buffer){
int words = get_words(buffer);
char *newbuff[words];
char *ptr;
int count = 0;
int count2 = 0;
char ch = '\n';
ptr = buffer;
bzero(newbuff, sizeof(newbuff));
for (count = 0; count < 100; count ++){
ch = buffer[count];
if (isblank(ch) || buffer[count] == '\0'){
buffer[count] = '\0';
if((newbuff[count2] = (char *)malloc(strlen(buffer))) == NULL) {
printf("MALLOC ERROR!\n");
exit(-1);
}
strcpy(newbuff[count2], ptr);
printf("\n%s\n",newbuff[count2]);
ptr = &buffer[count + 1];
count2 ++;
}
}
}
Although the output is what I want, I have really many black spaces after the final word displayed, and the malloc() returns NULL so the MALLOC ERROR! is displayed in the end.
I can understand that there is a mistake at my malloc() implementation, but I do not know what it is.
Is there another more elegant or generally better way to do it?
http://www.cplusplus.com/reference/clibrary/cstring/strtok/
Take a look at this, and use whitespace characters as the delimiter. If you need more hints let me know.
From the website:
char * strtok ( char * str, const char * delimiters );
On a first call, the function expects a C string as argument for str, whose first character is used as the starting location to scan for tokens. In subsequent calls, the function expects a null pointer and uses the position right after the end of last token as the new starting location for scanning.
Once the terminating null character of str is found in a call to strtok, all subsequent calls to this function (with a null pointer as the first argument) return a null pointer.
Parameters
str
C string to truncate.
Notice that this string is modified by being broken into smaller strings (tokens).
Alternativelly [sic], a null pointer may be specified, in which case the function continues scanning where a previous successful call to the function ended.
delimiters
C string containing the delimiter characters.
These may vary from one call to another.
Return Value
A pointer to the last token found in string.
A null pointer is returned if there are no tokens left to retrieve.
Example
/* strtok example */
#include <stdio.h>
#include <string.h>
int main ()
{
char str[] ="- This, a sample string.";
char * pch;
printf ("Splitting string \"%s\" into tokens:\n",str);
pch = strtok (str," ,.-");
while (pch != NULL)
{
printf ("%s\n",pch);
pch = strtok (NULL, " ,.-");
}
return 0;
}
For the fun of it here's an implementation based on the callback approach:
const char* find(const char* s,
const char* e,
int (*pred)(char))
{
while( s != e && !pred(*s) ) ++s;
return s;
}
void split_on_ws(const char* s,
const char* e,
void (*callback)(const char*, const char*))
{
const char* p = s;
while( s != e ) {
s = find(s, e, isspace);
callback(p, s);
p = s = find(s, e, isnotspace);
}
}
void handle_word(const char* s, const char* e)
{
// handle the word that starts at s and ends at e
}
int main()
{
split_on_ws(some_str, some_str + strlen(some_str), handle_word);
}
malloc(0) may (optionally) return NULL, depending on the implementation. Do you realize why you may be calling malloc(0)? Or more precisely, do you see where you are reading and writing beyond the size of your arrays?
Consider using strtok_r, as others have suggested, or something like:
void printWords(const char *string) {
// Make a local copy of the string that we can manipulate.
char * const copy = strdup(string);
char *space = copy;
// Find the next space in the string, and replace it with a newline.
while (space = strchr(space,' ')) *space = '\n';
// There are no more spaces in the string; print out our modified copy.
printf("%s\n", copy);
// Free our local copy
free(copy);
}
Something going wrong is get_words() always returning one less than the actual word count, so eventually you attempt to:
char *newbuff[words]; /* Words is one less than the actual number,
so this is declared to be too small. */
newbuff[count2] = (char *)malloc(strlen(buffer))
count2, eventually, is always one more than the number of elements you've declared for newbuff[]. Why malloc() isn't returning a valid ptr, though, I don't know.
You should be malloc'ing strlen(ptr), not strlen(buf). Also, your count2 should be limited to the number of words. When you get to the end of your string, you continue going over the zeros in your buffer and adding zero size strings to your array.
Just as an idea of a different style of string manipulation in C, here's an example which does not modify the source string, and does not use malloc. To find spaces I use the libc function strpbrk.
int print_words(const char *string, FILE *f)
{
static const char space_characters[] = " \t";
const char *next_space;
// Find the next space in the string
//
while ((next_space = strpbrk(string, space_characters)))
{
const char *p;
// If there are non-space characters between what we found
// and what we started from, print them.
//
if (next_space != string)
{
for (p=string; p<next_space; p++)
{
if(fputc(*p, f) == EOF)
{
return -1;
}
}
// Print a newline
//
if (fputc('\n', f) == EOF)
{
return -1;
}
}
// Advance next_space until we hit a non-space character
//
while (*next_space && strchr(space_characters, *next_space))
{
next_space++;
}
// Advance the string
//
string = next_space;
}
// Handle the case where there are no spaces left in the string
//
if (*string)
{
if (fprintf(f, "%s\n", string) < 0)
{
return -1;
}
}
return 0;
}
you can scan the char array looking for the token if you found it just print new line else print the char.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main()
{
char *s;
s = malloc(1024 * sizeof(char));
scanf("%[^\n]", s);
s = realloc(s, strlen(s) + 1);
int len = strlen(s);
char delim =' ';
for(int i = 0; i < len; i++) {
if(s[i] == delim) {
printf("\n");
}
else {
printf("%c", s[i]);
}
}
free(s);
return 0;
}
char arr[50];
gets(arr);
int c=0,i,l;
l=strlen(arr);
for(i=0;i<l;i++){
if(arr[i]==32){
printf("\n");
}
else
printf("%c",arr[i]);
}
I am trying to build a program that uses dynamic allocation to build an array of strings.
After the user finishes to enter the words he wants into the array i want to print the array one word after the other. I am using pointers to pointers, however it doesn't seem to work:
#define SIZE 256
void paintWords(char **words, int count_words);
void main() {
char **words = NULL;
int flag = 1;
char buffer[SIZE];
int count_words = 0;
char *curr_word;
while (flag)
{
_flushall();
printf("Enter a word:");
gets(buffer);
words = (char**)realloc(words,++count_words*sizeof(char*));
curr_word = (char*)malloc(strlen(buffer) + 1);
words[count_words - 1] = curr_word;
printf("Do you wish to continue(0-no, 1-yes):");
scanf("%d", &flag);
}
paintWords(words, count_words);
}
void paintWords(char **words, int count_words) {
int j = 0;
for (int i = 0; i < count_words; i++)
{
printf("%s\n", words[i][j]);
}
}
Copy buffer to your malloc'ed block with strcpy
strcpy(curr_word, buffer);
you are discarding the read word since you don't put it anywhere
Don't use gets use fgets instead
fgets(buffer, sizeof(buffer), stdin);
this would prevent a buffer overflow.
This is just the jst which in your case is the 0th character of the word
printf("%s\n", words[i][j]);
change it to
printf("%s\n", words[i]);
turn compiler warnings on, it would tell you about printf expecting a char * and recieving char instead.
Also consider the following:
main() should return int.
You don't need to cast malloc.
Don't overwrite your pointer with realloc, use a temporary pointer and assign it to array on success only. Otherwise if realloc returns NULL you will not be able to free(array) for example.
++count_words
words = realloc(words,count_words*sizeof(char*));
words[count_words-1] = malloc(strlen(buffer) + 1);
strcpy(words[count_words-1],buffer);
Later print the array
printf("%s\n",words[i]);
realloc() can fail so
char *temp = realloc(words,count_words*sizeof(char*));
if(temp != NULL)
words = temp;
Few other fixes will be
You shouldn't be using gets which is no more a standard. Use fgets() and note that fgets() comes with a newline character
Check the code below:
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define SIZE 256
void paintWords(char **words, int count_words);
void main() {
char **words = NULL,ch;
int flag = 1;
char buffer[SIZE];
int count_words = 0;
//char *curr_word;
while (flag)
{
printf("Enter a word:");
fgets(buffer,sizeof(buffer),stdin);
words = (char**)realloc(words,++count_words*sizeof(char*));
words[count_words - 1] = (char*)malloc(strlen(buffer) + 1);
strcpy(words[count_words-1],buffer);
printf("Do you wish to continue(0-no, 1-yes):");
scanf("%d", &flag);
while((ch = getchar()) != '\n');
}
paintWords(words, count_words);
}
void paintWords(char **words, int count_words) {
int i;
for (i=0; i < count_words; i++)
{
printf("%s", words[i]);
}
}
Simple question:
If i have a line in an input file that looks looks like:
Hello#Great#Day#Today
how can I scan in each word individually as its own array, in other words tell C to stop scanning when it reaches the # character and then go in the next iteration of the loop to scan the next word as a separate array?
This is assuming you are reading through stdin. Definitely take a look at #Whoz kick start approach as well (very similar to this).
What you would want to do is create a dynamic array and populate it with every byte read through stdin. You would then want to create an array of character pointers that will point to the first character in every "word", where you define a word as every character before a '#' character (delimiter). You would then iterate through that array of characters and populate the array of character pointers with the memory addresses of the first character in each word.
Use strtok() to tokenize your input by the specified character.
http://www.cplusplus.com/reference/cstring/strtok/
char str[] ="- This, a sample string.";
char * pch;
printf ("Splitting string \"%s\" into tokens:\n",str);
pch = strtok (str,"#");
while (pch != NULL)
{
printf ("%s\n",pch);
pch = strtok (NULL, "#");
}
In two stages, I have used something like this:
#include <ansi_c.h>
//tokenizing a string
int GetCount(char *in, char *delim, int *m);
int GetStrings(char *in, char *delim, int count, char **out);
void main(void)
{
int count, maxlen, i;
char inpString[]={"Hello#Greatest#Day#Today"};
char *resultBuf[10];
//get a count of strings to store
count = GetCount(inpString, "#", &maxlen);
for(i=0;i<10;i++)
{
resultBuf[i] = calloc(maxlen+1, sizeof(char));
}
//Store strings in arrays
GetStrings(inpString, "#", count, resultBuf);
for(i=0;i<count;i++)
{
printf("%s\n", resultBuf[i]);
free(resultBuf[i];
}
}
//Gets count of tokens (delimited strings)
int GetCount(char *in, char *delim, int *m)
{
char *buf=0;
char temp1[10]={0};
char *inStr;
int count = 0;
int max = 0, keepMax = 0;
if(in)
{
inStr = calloc(strlen(in)+1, sizeof(char));
strcpy(inStr, in);
if(strlen(inStr) > 1)
{
count = 0;
buf = strtok(inStr, delim);
while(buf)
{
strcpy(temp1, buf);
max = strlen(temp1);
(max > keepMax)?(keepMax = max):(keepMax == keepMax);
count++;
buf = strtok(NULL, delim);
}
*m = keepMax;
}
free(inStr);
}
return count;
}
//Gets array of strings
int GetStrings(char *in, char *delim, int count, char **out)
{
char *buf=0;
char *inStr;
int i = 0;
if(in)
{
inStr = calloc(strlen(in)+1, sizeof(char));
strcpy(inStr, in);
if(strlen(inStr) > 1)
{
buf = strtok(inStr, delim);
while(buf)
{
strcpy(out[i], buf);
buf = strtok(NULL, delim);
i++;
}
}
free(inStr);
}
return 0;
}
I want to write a program in C that displays each word of a whole sentence (taken as input) at a seperate line. This is what I have done so far:
void manipulate(char *buffer);
int get_words(char *buffer);
int main(){
char buff[100];
printf("sizeof %d\nstrlen %d\n", sizeof(buff), strlen(buff)); // Debugging reasons
bzero(buff, sizeof(buff));
printf("Give me the text:\n");
fgets(buff, sizeof(buff), stdin);
manipulate(buff);
return 0;
}
int get_words(char *buffer){ // Function that gets the word count, by counting the spaces.
int count;
int wordcount = 0;
char ch;
for (count = 0; count < strlen(buffer); count ++){
ch = buffer[count];
if((isblank(ch)) || (buffer[count] == '\0')){ // if the character is blank, or null byte add 1 to the wordcounter
wordcount += 1;
}
}
printf("%d\n\n", wordcount);
return wordcount;
}
void manipulate(char *buffer){
int words = get_words(buffer);
char *newbuff[words];
char *ptr;
int count = 0;
int count2 = 0;
char ch = '\n';
ptr = buffer;
bzero(newbuff, sizeof(newbuff));
for (count = 0; count < 100; count ++){
ch = buffer[count];
if (isblank(ch) || buffer[count] == '\0'){
buffer[count] = '\0';
if((newbuff[count2] = (char *)malloc(strlen(buffer))) == NULL) {
printf("MALLOC ERROR!\n");
exit(-1);
}
strcpy(newbuff[count2], ptr);
printf("\n%s\n",newbuff[count2]);
ptr = &buffer[count + 1];
count2 ++;
}
}
}
Although the output is what I want, I have really many black spaces after the final word displayed, and the malloc() returns NULL so the MALLOC ERROR! is displayed in the end.
I can understand that there is a mistake at my malloc() implementation, but I do not know what it is.
Is there another more elegant or generally better way to do it?
http://www.cplusplus.com/reference/clibrary/cstring/strtok/
Take a look at this, and use whitespace characters as the delimiter. If you need more hints let me know.
From the website:
char * strtok ( char * str, const char * delimiters );
On a first call, the function expects a C string as argument for str, whose first character is used as the starting location to scan for tokens. In subsequent calls, the function expects a null pointer and uses the position right after the end of last token as the new starting location for scanning.
Once the terminating null character of str is found in a call to strtok, all subsequent calls to this function (with a null pointer as the first argument) return a null pointer.
Parameters
str
C string to truncate.
Notice that this string is modified by being broken into smaller strings (tokens).
Alternativelly [sic], a null pointer may be specified, in which case the function continues scanning where a previous successful call to the function ended.
delimiters
C string containing the delimiter characters.
These may vary from one call to another.
Return Value
A pointer to the last token found in string.
A null pointer is returned if there are no tokens left to retrieve.
Example
/* strtok example */
#include <stdio.h>
#include <string.h>
int main ()
{
char str[] ="- This, a sample string.";
char * pch;
printf ("Splitting string \"%s\" into tokens:\n",str);
pch = strtok (str," ,.-");
while (pch != NULL)
{
printf ("%s\n",pch);
pch = strtok (NULL, " ,.-");
}
return 0;
}
For the fun of it here's an implementation based on the callback approach:
const char* find(const char* s,
const char* e,
int (*pred)(char))
{
while( s != e && !pred(*s) ) ++s;
return s;
}
void split_on_ws(const char* s,
const char* e,
void (*callback)(const char*, const char*))
{
const char* p = s;
while( s != e ) {
s = find(s, e, isspace);
callback(p, s);
p = s = find(s, e, isnotspace);
}
}
void handle_word(const char* s, const char* e)
{
// handle the word that starts at s and ends at e
}
int main()
{
split_on_ws(some_str, some_str + strlen(some_str), handle_word);
}
malloc(0) may (optionally) return NULL, depending on the implementation. Do you realize why you may be calling malloc(0)? Or more precisely, do you see where you are reading and writing beyond the size of your arrays?
Consider using strtok_r, as others have suggested, or something like:
void printWords(const char *string) {
// Make a local copy of the string that we can manipulate.
char * const copy = strdup(string);
char *space = copy;
// Find the next space in the string, and replace it with a newline.
while (space = strchr(space,' ')) *space = '\n';
// There are no more spaces in the string; print out our modified copy.
printf("%s\n", copy);
// Free our local copy
free(copy);
}
Something going wrong is get_words() always returning one less than the actual word count, so eventually you attempt to:
char *newbuff[words]; /* Words is one less than the actual number,
so this is declared to be too small. */
newbuff[count2] = (char *)malloc(strlen(buffer))
count2, eventually, is always one more than the number of elements you've declared for newbuff[]. Why malloc() isn't returning a valid ptr, though, I don't know.
You should be malloc'ing strlen(ptr), not strlen(buf). Also, your count2 should be limited to the number of words. When you get to the end of your string, you continue going over the zeros in your buffer and adding zero size strings to your array.
Just as an idea of a different style of string manipulation in C, here's an example which does not modify the source string, and does not use malloc. To find spaces I use the libc function strpbrk.
int print_words(const char *string, FILE *f)
{
static const char space_characters[] = " \t";
const char *next_space;
// Find the next space in the string
//
while ((next_space = strpbrk(string, space_characters)))
{
const char *p;
// If there are non-space characters between what we found
// and what we started from, print them.
//
if (next_space != string)
{
for (p=string; p<next_space; p++)
{
if(fputc(*p, f) == EOF)
{
return -1;
}
}
// Print a newline
//
if (fputc('\n', f) == EOF)
{
return -1;
}
}
// Advance next_space until we hit a non-space character
//
while (*next_space && strchr(space_characters, *next_space))
{
next_space++;
}
// Advance the string
//
string = next_space;
}
// Handle the case where there are no spaces left in the string
//
if (*string)
{
if (fprintf(f, "%s\n", string) < 0)
{
return -1;
}
}
return 0;
}
you can scan the char array looking for the token if you found it just print new line else print the char.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main()
{
char *s;
s = malloc(1024 * sizeof(char));
scanf("%[^\n]", s);
s = realloc(s, strlen(s) + 1);
int len = strlen(s);
char delim =' ';
for(int i = 0; i < len; i++) {
if(s[i] == delim) {
printf("\n");
}
else {
printf("%c", s[i]);
}
}
free(s);
return 0;
}
char arr[50];
gets(arr);
int c=0,i,l;
l=strlen(arr);
for(i=0;i<l;i++){
if(arr[i]==32){
printf("\n");
}
else
printf("%c",arr[i]);
}