tests: More work on error handling

tests/stdio/freopen.c

@@ -3,8 +3,10 @@
 #include "test_helpers.h"
 
 int main(void) {
-	freopen("stdio/stdio.in", "r", stdin);
-	char in[6];
-	fgets(in, 6, stdin);
-	printf("%s\n", in); // should print Hello
+    FILE *f = freopen("stdio/stdio.in", "r", stdin);
+    ERROR_IF(freopen, f, == NULL);
+
+    char in[6];
+    fgets(in, 6, stdin);
+    printf("%s\n", in); // should print Hello
 }

tests/stdio/fseek.c

@@ -7,11 +7,14 @@ int main(void) {
     FILE *f = fopen("stdio/stdio.in", "r");
     ERROR_IF(fopen, f, == NULL);
 
-    if (fseek(f, 14, SEEK_CUR) < 0) {
-        puts("fseek error");
-        exit(EXIT_FAILURE);
-    }
+    int status = fseek(f, 14, SEEK_CUR);
+    ERROR_IF(fseek, status, == -1);
+    UNEXP_IF(fseek, status, != 0);
+
     char buffer[256];
     printf("%s", fgets(buffer, 256, f));
-    printf("ftell: %ld\n", ftello(f));
+
+    off_t pos = ftello(f);
+    ERROR_IF(ftello, pos, == -1);
+    printf("ftell: %ld\n", pos);
 }

tests/stdio/popen.c

@@ -5,7 +5,7 @@
 
 int main(void) {
     FILE *fp = popen("ls -1 example_dir", "r");
-    ERROR_IF(fopen, fp, == NULL);
+    ERROR_IF(popen, fp, == NULL);
 
     char path[256] = { 0 };
     while (fgets(path, 256, fp) != NULL) {

tests/stdio/rename.c

@@ -9,19 +9,46 @@
 static char oldpath[] = "old-name.out";
 static char newpath[] = "new-name.out";
 static char str[] = "Hello, World!";
-int str_len = 13;
 
 int main(void) {
-    char buf[14];
-    buf[13] = 0x00;
+    char buf[14] = { 0 };
+
+    // Create old file
     int fd = creat(oldpath, 0777);
-    write(fd, str, str_len);
-    close(fd);
-    rename(oldpath, newpath);
+    ERROR_IF(creat, fd, == -1);
+    UNEXP_IF(creat, fd, < 0);
+
+    int written_bytes = write(fd, str, strlen(str));
+    ERROR_IF(write, written_bytes, == -1);
+
+    int c1 = close(fd);
+    ERROR_IF(close, c1, == -1);
+    UNEXP_IF(close, c1, != 0);
+
+    // Rename old file to new file
+    int rn_status = rename(oldpath, newpath);
+    ERROR_IF(rename, rn_status, == -1);
+    UNEXP_IF(rename, rn_status, != 0);
+
+    // Read new file
     fd = open(newpath, O_RDONLY);
-    read(fd, buf, str_len);
-    close(fd);
-    remove(newpath);
+    ERROR_IF(open, fd, == -1);
+    UNEXP_IF(open, fd, < 0);
+
+    int read_bytes = read(fd, buf, strlen(str));
+    ERROR_IF(read, read_bytes, == -1);
+    UNEXP_IF(read, read_bytes, < 0);
+
+    int c2 = close(fd);
+    ERROR_IF(close, c2, == -1);
+    UNEXP_IF(close, c2, != 0);
+
+    // Remove new file
+    int rm_status = remove(newpath);
+    ERROR_IF(remove, rm_status, == -1);
+    UNEXP_IF(remove, rm_status, != 0);
+
+    // Compare file contents
     if (strcmp(str, buf) == 0) {
         exit(EXIT_SUCCESS);
     } else {