Removing a newline from the middle of a string using getchar - c

Question

Right now I have a string looking like this:
A sentence
with a newline.
I'm reading the string in via console input like so:
ch = getchar();
while (ch != '.') {
msg[i] = ch;
i++;
ch = getchar();
}
And, after reading it in, I remove the whitespace present by doing this in a function and applying to the msg char array:
char *remove_white_spaces(char *str) {
int i = 0, j = 0;
while (str[i]) {
if (str[i] != ' ')
str[j++] = str[i];
i++;
}
str[j] = '\0';
return str;
}
I've tried looping over it and stopping at \n but that leaves an output of "Asentence", as the string terminates as the \n is set to 0.
Whole main:
int main(void) {
char msg[MAX_MSG_LEN+1];
char ch;
int i = 0;
ch = getchar();
while (ch != '.') {
msg[i] = ch;
i++;
ch = getchar();
}
msg[i] = '.';
msg[i + 1] = '\0';
remove_white_spaces(msg);
printf("%s\n", msg);
return 0;
}

Answer 1

You can use the isspace function to test for and skip any/all whitespace characters, include the normal space and the newline character(s):
#include <ctype.h> // For definition of "isspace"
char *remove_white_spaces(char *str) {
int i = 0, j = 0;
while (str[i]) {
if (!isspace((unsigned char)(str[i])))
str[j++] = str[i];
i++;
}
str[j] = '\0';
return str;
}
On the reason for casting the argument to isspace to an unsigned char, see this discussion.

Answer 2

Function removing and replacing any chars in the string.
toRemove - chars to remove
addSpace - replace with space
allowMultiple - allow multiple spaces when replacing more adjanced
characters
allowEdges - allow adding spaces at the from and at the end
char *removeChars(char *str, const char *toRemove, const int addSpace, const int allowMultiple, int const allowEdges)
{
char *rd = str, *wr = str;
int replaced = 0;
if(rd)
{
while(*rd)
{
if(strchr(toRemove, *rd))
{
if(addSpace)
{
if(!replaced || allowMultiple)
{
if(wr != str || (wr == str && allowEdges))
{
*wr++ = ' ';
replaced = 1;
}
}
}
}
else
{
*wr++ = *rd;
replaced = 0;
}
rd++;
}
if(allowEdges) *wr = 0;
else
while((wr - 1) > str)
{
if(*(wr - 1) == ' ') {*(wr - 1) = 0; wr--;}
else break;
}
}
return str;
}
int main(void)
{
char str[] = "%%%%%A sentence\n\n\nwith!##$%^a newline.%%%%%%%";
printf("`%s`\n", removeChars(str,"\n!##$%^", 1, 0, 0));
}

Answer 3

Following the suggestion of #MarkBenningfield I did the following and checked for '\n' and just replaced it with a space.
while (ch != '.') {
msg[i] = ch;
i++;
ch = getchar();
if (ch == '\n') {
ch = ' ';
}
}