Signal Handler running multiples times - c

Question

Currently writing a basic shell that handles signal interrupt with variety of other functions.
int numberOfCommands = 0;
int signalHandlerFired = 0;
char history[HISTORY_DEPTH][COMMAND_LENGTH];
void handle_SIGINT(){
writeHistory();
signalHandlerFired = 1;
}
int main(int argc, char* argv[])
{
char input_buffer[COMMAND_LENGTH];
char *tokens[NUM_TOKENS];
char cwd[COMMAND_LENGTH];
struct sigaction handler;
handler.sa_handler = handle_SIGINT;
sigaction(SIGINT, &handler, NULL);
while (true) {
signalHandlerFired = 0;
getcwd(cwd, sizeof(cwd));
write(STDOUT_FILENO, cwd, strlen(cwd));
write(STDOUT_FILENO, "> ", strlen("> "));
_Bool in_background = false;
read_command(input_buffer, tokens, &in_background);
if (signalHandlerFired == 1) {
continue;
}
char exclamationCommand[2];
exclamationCommand[0] = tokens[0][0];
exclamationCommand[1] = '\0';
char* hcNumber = &tokens[0][1];
if (strcmp(&exclamationCommand[0], "!") == 0) {
if (atoi(hcNumber) == 0) {
} else {
retrieveHistory(hcNumber, numberOfCommands, input_buffer, tokens, in_background);
}
continue;
}
insertHistory(&numberOfCommands, input_buffer, tokens);
//exit
if (strcmp(tokens[0], "exit") == 0) {
exit(0);
}
//pwd
if (strcmp(tokens[0], "pwd") == 0) {
getcwd(cwd, sizeof(cwd));
write(STDOUT_FILENO, cwd, strlen(cwd));
write(STDOUT_FILENO, "\n", strlen("\n"));
continue;
}
//cd
if (strcmp(tokens[0], "cd") == 0) {
int dcSuccess = chdir(tokens[1]);
if (dcSuccess == -1) {
write(STDOUT_FILENO, "Invalid Directory", strlen("Invalid Directory"));
write(STDOUT_FILENO, "\n", strlen("\n"));
}
continue;
}
//history
if (strcmp(tokens[0], "history") == 0) {
writeHistory(tokens[0]);
}
executeCommand(numberOfCommands, input_buffer, tokens, in_background);
}
return 0;
}
In the while loop in main() which gets inputs from the command line and does processing depending on the type of command entered, the signal handler will run twice or more depending on...is what I don't know.
The purpose of SIGINT [Ctrl+C] interrupt is to display the command history. This works fine if i run it once, but after..
/home/ahn/> ls
Token: ls
a.out Makefile.txt~ shell shell.c~ shellsample.c~
Makefile mystring_sol.c shell.c shell.o
/home/ahn/> ^C
History:
1 ls
---------------Second Run
/home/ahn/> ks
Token: ks
Unknown Command
/home/ahn/> ^C
History:
Number Of Commands: 2
1 ls
2 ks
/home/ahn/>
History:
Number Of Commands: 2
1 ls
2 ks
/home/ahn/>
I think I don't have a clear understanding when interrupts happen, at which point in the program is returning too. Moreover, I have no idea why it is running twice. I will provide any function definitions if needed.
Also, the char ks comes out corrupted. Full core here if needed.