#include "readwrite.h"
#include <stddef.h> /* size_t */
-#include <stdint.h> /* uint8_t, uint16_t, uint32_t */
+#include <stdint.h> /* uint8_t, uint16_t, uint32_t, UINT32_MAX */
#include <stdio.h> /* FILE, fseek(), sprintf(), fgets(), fgetc(), ferror(),
- * fputc(), fwrite(), fclose(), fopen()
+ * fputc(), fwrite(), fclose(), fopen(), clearerr()
*/
+#include <stdlib.h> /* free() */
#include <string.h> /* strlen() */
-#include <unistd.h> /* for access(), unlink() */
+#include <unistd.h> /* access(), unlink() */
#include "rexit.h" /* exit_err(), exit_trouble() */
+#include "try_malloc.h" /* try_malloc() */
+
+
+
+/* Return "path" + suffix "_tmp". Value is malloc'd, must be free externally. */
+static char * build_temp_path(char * path);
+
+
+
+static char * build_temp_path(char * path)
+{
+ char * f_name = "build_temp_path";
+ char * suffix_tmp = "_tmp";
+ uint16_t size = strlen(path) + strlen(suffix_tmp) + 1;
+ char * path_tmp = try_malloc(size, f_name);
+ int test = sprintf(path_tmp, "%s%s", path, suffix_tmp);
+ exit_trouble(test < 0, f_name, "sprintf()");
+ return path_tmp;
+}
extern FILE * try_fopen(char * path, char * mode, char * f)
{
+ char * f_name = "try_fopen()";
char * msg1 = "Trouble in ";
char * msg2 = " with fopen() (mode '";
char * msg3 = "') on path '";
char * msg4 = "'.";
uint16_t size = strlen(msg1) + strlen(msg2) + strlen(msg3) + strlen(msg4)
+ strlen(f) + strlen(path) + strlen(mode) + 1;
- char msg[size];
- sprintf(msg, "%s%s%s%s%s%s%s", msg1, f, msg2, mode, msg3, path, msg4);
+ char * msg = try_malloc(size, f_name);
+ int test = sprintf(msg, "%s%s%s%s%s%s%s", msg1,f,msg2,mode,msg3,path,msg4);
+ exit_trouble(test < 0, f_name, "sprintf()");
FILE * file_p = fopen(path, mode);
exit_err(NULL == file_p, msg);
+ free(msg);
return file_p;
}
extern int try_fgetc(FILE * file, char * f)
{
+ clearerr(file); /* OSX' (BSD?) fgetc() needs this to undo previous EOFs. */
int test = fgetc(file);
exit_trouble(EOF == test && ferror(file), f, "fgetc()");
return test;
-extern void try_fclose_unlink_rename(FILE * file, char * p1, char * p2,
- char * f)
+extern FILE * atomic_write_start(char * path, char ** path_tmp)
+{
+ char * f_name = "atomic_write_start()";
+ *path_tmp = build_temp_path(path);
+ return try_fopen(*path_tmp, "w", f_name);
+}
+
+
+
+extern void atomic_write_finish(FILE * file, char * path, char * path_tmp)
{
- try_fclose(file, f);
+ char * f_name = "atomic_write_finish()";
+ try_fclose(file, f_name);
char * msg1 = "Trouble in ";
char * msg4 = "'.";
- if (!access(p2, F_OK))
+ if (!access(path, F_OK))
{
char * msg2 = " with unlink() on path '";
uint16_t size = strlen(msg1) + strlen(msg2) + strlen(msg4)
- + strlen(f) + strlen(p2) + 1;
- char msg[size];
- sprintf(msg, "%s%s%s%s%s", msg1, f, msg2, p2, msg4);
- exit_err(unlink(p2), msg);
+ + strlen(f_name) + strlen(path) + 1;
+ char * msg = try_malloc(size, f_name);
+ int test = sprintf(msg, "%s%s%s%s%s", msg1, f_name, msg2, path, msg4);
+ exit_trouble(test < 0, f_name, "sprintf()");
+ exit_err(unlink(path), msg);
+ free(msg);
}
char * msg2 = " with rename() from '";
char * msg3 = "' to '";
- uint16_t size = strlen(msg1) + strlen(f) + strlen(msg2) + strlen(p1)
- + strlen(msg3) + strlen(p2) + strlen(msg4) + 1;
- char msg[size];
- sprintf(msg, "%s%s%s%s%s%s%s", msg1, f, msg2, p1, msg3, p2, msg4);
- exit_err(rename(p1, p2), msg);
+ uint16_t size = strlen(msg1) + strlen(f_name) + strlen(msg2) +
+ + strlen(path_tmp) + strlen(msg3) + strlen(path)
+ + strlen(msg4) + 1;
+ char * msg = try_malloc(size, f_name);
+ int test = sprintf(msg, "%s%s%s%s%s%s%s",
+ msg1, f_name, msg2, path_tmp, msg3, path, msg4);
+ exit_trouble(test < 0, f_name, "sprintf()");
+ exit_err(rename(path_tmp, path), msg);
+ free(msg);
+ free(path_tmp);
+}
+
+
+
+extern void detect_atomic_leftover(char * path)
+{
+ char * f_name = "detect_atomic_leftover()";
+ char * path_tmp = build_temp_path(path);
+ char * part1 = "Found file '";
+ char * part2 = "' that may be a leftover from an aborted previous attempt "
+ "to write '";
+ char * part3 = "'. Aborting until the matter is solved by (re-)moving it.";
+ uint32_t size = strlen(part1) + strlen(path_tmp) + strlen(part2)
+ + strlen(path) + strlen(part3) + 1;
+ char * msg = try_malloc(size, f_name);
+ int test = sprintf(msg, "%s%s%s%s%s", part1, path_tmp, part2, path, part3);
+ exit_trouble(test < 0, f_name, "sprintf()");
+ exit_err(!access(path_tmp, F_OK), msg);
+ free(msg);
+ free(path_tmp);
}
break;
}
c_count++;
+ exit_trouble(UINT32_MAX == c_count, f_name, "too large text file line");
if ('\n' == c)
{
if (c_count > linemax)