Trying to write teh prompt command in C.

c/Makefile

@@ -0,0 +1,2 @@
+all:
+	cc -Wall -Wextra -pedantic -o _z_prompt_command z_prompt_command.c

c/z_prompt_command.c

@@ -0,0 +1,58 @@
+// PROMPT_COMMAND for z.sh
+
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+int main() {
+    char * _Z_DATA;
+    char datafile[PATH_MAX];
+    char tmpfile[PATH_MAX];
+    FILE *read;
+    FILE *write;
+    char line[LINE_MAX];
+    char cwd[PATH_MAX];
+    char pth[PATH_MAX];
+    float rank;
+    int timestamp;
+    time_t epoch = time(NULL);
+    int found = 0;
+
+    if (getcwd(cwd, sizeof(cwd)) == NULL) return EXIT_FAILURE;
+
+    _Z_DATA = getenv("_Z_DATA");
+    if( _Z_DATA == NULL ) {
+        sprintf(datafile, "%s/.z", getenv("HOME"));
+    } else {
+        sprintf(datafile, "%s", _Z_DATA);
+    }
+
+    read = fopen(datafile, "r");
+    if (read == NULL) return EXIT_FAILURE;
+
+    srand(time(NULL));
+    sprintf(tmpfile, "%s.%d", datafile, rand());
+
+    write = fopen(tmpfile, "w");
+    if (write == NULL) return EXIT_FAILURE;
+
+    while (fgets(line, sizeof line, read) != NULL) {
+        sscanf(line, "%[^|]|%f|%d\n", pth, &rank, &timestamp);
+        if (strcmp(pth, cwd) == 0) {
+            fprintf(write, "%s|%f|%d\n", pth, rank + 1, (int) epoch);
+            found = 1;
+        } else fprintf(write, "%s", line);
+    }
+    if (!found) fprintf(write, "%s|1|%d\n", cwd, (int) epoch);
+
+    fclose(read);
+    fclose(write);
+
+    if (rename(tmpfile, datafile) == 0) return EXIT_SUCCESS;
+
+    return EXIT_FAILURE;
+
+}