1 files changed, 44 insertions, 0 deletions
diff --git a/src/ctof.c b/src/ctof.c
new file mode 100644
index 0000000..e61cfcd
--- /dev/null
+++ b/src/ctof.c
@@ -0,0 +1,44 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h> // for errno
+#include <limits.h> // for INT_MAX, INT_MIN
+
+
+/*
+    F = C x 9/5 + 32
+*/
+
+int
+main(int argc, char *argv[])
+{
+
+    if (argc < 2) {
+        printf("Usage: %s number\n", argv[0]);
+        return 1;
+    }
+
+    char *endptr;
+
+    errno = 0; // reset errno
+
+    long value = strtol(argv[1], &endptr, 10); // base 10
+
+    if (endptr == argv[1]) {
+        printf("Error: No digits were found\n");
+        return 1;
+    }
+    if (*endptr != '\0') {
+        printf("Warning: Trailing characters after number: %s\n", endptr);
+        return 1;
+    }
+    if ((value == LONG_MAX || value == LONG_MIN) && errno == ERANGE) {
+        printf("Error: Number out of range\n");
+        return 1;
+    }
+
+    float fah = value * 9/5 + 32;
+
+    printf("Fahrenheit: %0.f\n", fah);
+
+    return 0;
+}