changed code removed main from each file

Makefile

@@ -2,16 +2,12 @@ CC = gcc
 CFLAGS = -Wall -Wextra -std=c11
 SRCDIR = ./c-basic
 SRC = $(wildcard $(SRCDIR)/*.c)
-OBJ = $(SRC:.c=.o)
+OBJ = $(patsubst $(SRCDIR)/%.c, $(SRCDIR)/%.o, $(SRC))
 TARGET = main
-
 all: $(TARGET)
-
 $(TARGET): $(OBJ)
 	$(CC) $(CFLAGS) -o $@ $^
-
 $(SRCDIR)/%.o: $(SRCDIR)/%.c
 	$(CC) $(CFLAGS) -c $< -o $@
-
 clean:
 	rm -f $(OBJ) $(TARGET)

c-basic/float_double.c

@@ -1,6 +1,6 @@
 #include <stdio.h>
 
-int main()
+int my_float()
 {
   float f;
   double d;

c-basic/foo.c

@@ -6,9 +6,3 @@ int foo()
 
   return 0;
 }
-
-int main()
-{
-  foo();
-  return 0;
-}

c-basic/hello.c

@@ -1,6 +1,6 @@
 #include <stdio.h>
 
-int main()
+int hello()
 {
   printf("Hello C Programming Language 2025 Examples");
 

c-basic/hex_read_scanf.c

@@ -3,7 +3,7 @@
 int hex_scan()
 {
 
-  int a, b;
+  int a;
 
   printf("Enter a number : ");
 

c-basic/main.c

@@ -1,5 +1,11 @@
 #include <stdio.h>
-#include "hex_read_scanf.c"
+
+#ifndef HEX_READ_SCANF_H
+#define HEX_READ_SCANF_H
+
+extern void hex_scan();
+
+#endif // HEX_READ_SCANF_H
 
 int main()
 {

c-basic/print_example.c

@@ -1,6 +1,6 @@
 #include <stdio.h>
 
-int main()
+int print_example()
 {
   int a = 10, b = 20;
 

c-basic/print_example_with_scan.c

@@ -1,6 +1,6 @@
 #include <stdio.h>
 
-int main()
+int print_with_scan()
 {
   int a , b ;
 

c-basic/scanf_example.c

@@ -1,6 +1,6 @@
 #include <stdio.h>
 
-int main()
+int my_scan()
 {
   int a;
 

c-basic/scanf_example_two_numbers.c

@@ -1,6 +1,6 @@
 #include <stdio.h>
 
-int main()
+int scan_two_numbers()
 {
   int a, b;
 

c-basic/toplama.c

@@ -1,6 +1,6 @@
 #include <stdio.h>
 
-int main()
+int addition()
 {
   int a , b , c;