c does not follow the program operation procedure - c

Question

summary : system("clear"); isn't working well.
I'm using gcc, ubuntu 18.04 LTS version for c programming.
what I intended was "read each words and print from two text files. After finish read file, delay 3 seconds and erase terminal"
so I was make two text files, and using system("clear"); to erase terminal.
here is whole code.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
void printFiles(char *file1,char *file2,char *change1, char *change2){
FILE *f;
char *text = malloc(sizeof(char)*100);
f=fopen(file1,"r");
system("clear");
//while(!feof(f)){
while(EOF!=fscanf(f,"%s",text)){
//fscanf(f,"%s", text);
printf("%s ",text);
//usleep(20000);
}
//sleep(3);
fclose(f);
printf("\n");
//all comment problems are appear here. and if I give delay, such as usleep() or sleep, delay also appear here. Not appear each wrote part.
f=fopen(file2,"r");
//while(!feof(f)){
while(EOF!=fscanf(f,"%s",text)){
if(strcmp(text,"**,")==0){
strcpy(text,change1);
strcat(text,",");
}
else if(strcmp(text,"**")==0){
strcpy(text,change1);
}
else if(strcmp(text,"##.")==0){
strcpy(text,change2);
strcat(text,".");
}
else if(strcmp(text,"##,")==0){
strcpy(text,change2);
strcat(text,",");
}
printf("%s ",text);
//usleep(200000);
}
fclose(f);
free(text);
sleep(3); //here is problem. This part works in the above commented part "//all comment problems are appear here."
system("clear"); //here is problem. This part works in the above commented part "//all comment problems are appear here."
}
int main(){
char file1[100] = "./file1.txt";
char file2[100] = "./file2.txt";
char change1[100]="text1";
char change2[100]="text2";
printFiles(file1,file2,change1,change2);
return 0;
}
I'm very sorry, files and variables names are changed because of policy. Also, file contents also can not upload.
I can't find which part makes break Procedure-oriented programming. I think that was compiler error, because using one file read and system(clear); works well.
I also make two point variables, such as 'FILE *f1; FILE *f2; f1=fopen(file1); f2=fopen(file2)...`, but same result occur.
Is it compiler error? If it is, what should I do for fix these problem? Thanks.

Answer 1

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
void printFiles(char *file1,char *file2,char *change1, char *change2){
FILE *f;
char *text = malloc(sizeof(char)*100);
f=fopen(file1,"r");
system("clear");
//while(!feof(f)){
while(EOF!=fscanf(f,"%s",text)){
//fscanf(f,"%s", text);
printf("%s ",text);
fflush(stdout);
//usleep(20000);
}
//sleep(3);
fclose(f);
printf("\n");
//all comment problems are appear here. and if I give delay, such as usleep() or sleep, delay also appear here. Not appear each wrote part.
f=fopen(file2,"r");
//while(!feof(f)){
while(EOF!=fscanf(f,"%s",text)){
if(strcmp(text,"**,")==0){
strcpy(text,change1);
strcat(text,",");
}
else if(strcmp(text,"**")==0){
strcpy(text,change1);
}
else if(strcmp(text,"##.")==0){
strcpy(text,change2);
strcat(text,".");
}
else if(strcmp(text,"##,")==0){
strcpy(text,change2);
strcat(text,",");
}
printf("%s ",text);
fflush(stdout);// The answer.
//usleep(200000);
}
fclose(f);
free(text);
sleep(3); //here is problem. This part works in the above commented part "//all comment problems are appear here."
system("clear"); //here is problem. This part works in the above commented part "//all comment problems are appear here."
}
int main(){
char file1[100] = "./file1.txt";
char file2[100] = "./file2.txt";
char change1[100]="text1";
char change2[100]="text2";
printFiles(file1,file2,change1,change2);
return 0;
}
Hint for
That's probably just buffering. Do fflush(stdout); before you sleep. – melpomene
Thanks.

Answer 2

You can try this solution for delay.
#include <time.h>
#include <stdio.h>
void delay(double seconds)
{
const time_t start = time(NULL);
time_t current;
do
{
time(&current);
} while(difftime(current, start) < seconds);
}
int main(void)
{
printf("Just waiting...\n");
delay(3);
printf("...oh man, waiting for so long...\n");
return 0;
}
Following solution is pretty quite the same of previous one but with a clear terminal solution.
#include <time.h>
#include <stdio.h>
#ifdef _WIN32
#define CLEAR_SCREEN system ("cls");
#else
#define CLEAR_SCREEN puts("\x1b[H\x1b[2J");
#endif
void delay(double seconds)
{
const time_t start = time(NULL);
time_t current;
do
{
time(&current);
} while(difftime(current, start) < seconds);
}
int main(void)
{
printf("Just waiting...\n");
delay(2); //seconds
printf("...oh man, waiting for so long...\n");
delay(1);
CLEAR_SCREEN
return 0;
}