Differentiated try_fgetc() (fgetc() wrapper proper) and try_fgetc_noeof() (catches...

[plomrogue] / src / readwrite.h

diff --git a/src/readwrite.h b/src/readwrite.h
index 62e222a85467b8fe5ce42aa30f4037e34f3ff9c8..2e0ca9f47e858a57241c9b4595dffffadd8fe661 100644 (file)
--- a/src/readwrite.h
+++ b/src/readwrite.h
@@ -1,18 +1,64 @@
-/*   readwrite.h:
+/* readwrite.h:
  *
- *   Routines for reading/writing multibyte data from/to files. They ensure a
- *   defined endianness.
+ * Routines for reading and writing files.
  */
 
 #ifndef READWRITE_H
 #define READWRITE_H
 
-#include <stdio.h>
-#include <stdint.h>
+#include <stdio.h> /* for FILE typedef */
+#include <stdint.h> /* for uint8_t, uint16_t, uint32_t */
+
+
+
+/* Wrappers to calling from function called "f" of fopen(), fclose(), fgets()
+ * and fwrite() and calling exit_err() with appropriate error messages.
+ */
+extern FILE * try_fopen(char * path, char * mode, char * f);
+extern void try_fclose(FILE * file, char * f);
+extern void try_fwrite(void * ptr, size_t size, size_t nmemb, FILE * stream,
+                       char * f);
+extern void try_fputc(uint8_t c, FILE * file, char * f);
+
+/* Wrapper to calling fgets() from function called "f". The return code of
+ * fgets() is returned unless it is NULL *and* ferror() indicates that an error
+ * occured; otherwise end of file is assumed and NULL is returned properly.
+ */
+extern char * try_fgets(char * line, int size, FILE * file, char * f);
+
+/* Wrappers to calling fgetc() and (try_fgetc_noeof()) treating all EOFs returns
+ * as errors to call exit_trouble(), or (try_fgetc()) only if ferror() says so.
+ */
+extern int try_fgetc(FILE * file, char * f);
+extern uint8_t try_fgetc_noeof(FILE * file, char * f);
+
+/* Wrapper to successive call of fclose() from function called "f" on "file",
+ * then unlink() on file at "p2" if it exists, then rename() on "p1" to "p2".
+ * Used for handling atomic saving of files via temp files.
+ */
+extern void try_fclose_unlink_rename(FILE * file, char * p1, char * p2,
+                                     char * f);
+
+/* Wrapper: Call textfile_sizes() from function called "f" to get max line
+ * length (includes newline char) of "file", exit via exit_err() with
+ * exit_trouble() on failure.
+ */
+extern uint16_t get_linemax(FILE * file, char * f);
+
+/* Learn from "file" the largest line length (pointed to by "linemax_p"; length
+ * includes newline chars) and (pointed to by "n_lines_p" if it is not set to
+ * NULL) the number of lines (= number of newline chars).
+ *
+ * Returns 0 on success, 1 on error of fseek() (called to return to initial file
+ * reading position).
+ */
+extern uint8_t textfile_sizes(FILE * file, uint16_t * linemax_p,
+                              uint16_t * n_lines_p);
+
+/* Read/write via try_(fgetc|fputc)() uint32 values with defined endianness. */
+extern uint32_t read_uint32_bigendian(FILE * file);
+extern void write_uint32_bigendian(uint32_t x, FILE * file);
+
 
-extern uint16_t read_uint16_bigendian( FILE * file );
-extern uint32_t read_uint32_bigendian( FILE * file );
-extern void     write_uint16_bigendian( uint16_t x, FILE * file );
-extern void     write_uint32_bigendian( uint32_t x, FILE * file );
 
 #endif