New file default_modify.c. Fixed a typo on mysqld.cc

Changed name of function my_correct_default_file to
modify_defaults_file. Improved function and fixed some
bugs in it.


include/my_sys.h:
  Changed function name.
include/mysql_com.h:
  New function, modify_defaults_file()
libmysql/Makefile.shared:
  New file, default_modify.lo
libmysql/libmysql.def:
  New function, modify_defaults_file() and fixed version number.
libmysqld/libmysqld.def:
  New function, modify_defaults_file()
mysys/Makefile.am:
  New file, default_modify.c
mysys/default.c:
  Removed function from default.c. New, corresponding one is in default_modify.c,
  name is modify_defaults_file.
server-tools/instance-manager/commands.cc:
  Changed function name.
sql/mysqld.cc:
  Fixed typo.

mysys/default_modify.c

@@ -0,0 +1,164 @@
+/*
+  Add/remove option to the option file section.
+
+  SYNOPSYS
+    modify_defaults_file()
+    file_location     The location of configuration file to edit
+    option            option to look for
+    option value      The value of the option we would like to set
+    section_name      the name of the section
+    remove_option     This is true if we want to remove the option.
+                      False otherwise.
+  IMPLEMENTATION
+    We open the option file first, then read the file line-by-line,
+    looking for the section we need. At the same time we put these lines
+    into a buffer. Then we look for the option within this section and
+    change/remove it. In the end we get a buffer with modified version of the
+    file. Then we write it to the file, truncate it if needed and close it.
+
+  RETURN
+    0 - ok
+    1 - some error has occured. Probably due to the lack of resourses
+    2 - cannot open the file
+*/
+
+#include "my_global.h"
+#include "mysys_priv.h"
+#include "m_string.h"
+#include <my_dir.h>
+
+#define BUFF_SIZE 1024
+
+#ifdef __WIN__
+#define NEWLINE "\r\n"
+#define NEWLINE_LEN 2
+#else
+#define NEWLINE "\n"
+#define NEWLINE_LEN 1
+#endif
+
+uint modify_defaults_file(const char *file_location, const char *option,
+			  const char *option_value,
+			  const char *section_name, int remove_option)
+{
+  FILE *cnf_file;
+  struct stat file_stat;
+  char linebuff[BUFF_SIZE], tmp[BUFF_SIZE], *tmp_ptr, *src_ptr, *dst_ptr,
+       *file_buffer;
+  uint optlen, optval_len, sect_len;
+  my_bool in_section= FALSE;
+  DBUG_ENTER("modify_defaults_file");
+
+  optlen= strlen(option);
+  optval_len= strlen(option_value);
+  sect_len= strlen(section_name);
+
+  if (!(cnf_file= my_fopen(file_location, O_RDWR | O_BINARY, MYF(0))))
+    DBUG_RETURN(2);
+
+  /* my_fstat doesn't use the flag parameter */
+  if (my_fstat(fileno(cnf_file), &file_stat, MYF(0)))
+    goto err;
+
+  /*
+    Reserve space to read the contents of the file and some more
+    for the option we want to add.
+  */
+  if (!(file_buffer= (char*) my_malloc(sizeof(char)*
+				       (file_stat.st_size +
+					/* option name len */
+					optlen +
+					/* reserve space for newline */
+					NEWLINE_LEN +
+					/* reserve for '=' char */
+					1 +           
+					/* option value len */
+					optval_len), MYF(MY_WME))))
+    goto malloc_err;
+
+  for (dst_ptr= file_buffer, tmp_ptr= 0;
+       fgets(linebuff, BUFF_SIZE, cnf_file); )
+  {
+    /* Skip over whitespaces */
+    for (src_ptr= linebuff; my_isspace(&my_charset_latin1, *src_ptr);
+	 src_ptr++)
+    {}
+
+    if (in_section && !strncmp(src_ptr, option, optlen) &&
+	(*(src_ptr + optlen) == '=' ||
+	 my_isspace(&my_charset_latin1, *(src_ptr + optlen)) ||
+	 *(src_ptr + optlen) == '\0'))
+    {
+      /* The option under modifying was found in this section. Apply new. */
+      if (!remove_option)
+	dst_ptr= strmov(dst_ptr, tmp);
+      tmp_ptr= 0; /* To mark that we have already applied this */
+    }
+    else
+    {
+      /* If going to new group and we have option to apply, do it now */
+      if (tmp_ptr && *src_ptr == '[')
+      {
+	dst_ptr= strmov(dst_ptr, tmp);
+	tmp_ptr= 0;
+      }
+      dst_ptr= strmov(dst_ptr, linebuff);
+    }
+    /* Look for a section */
+    if (*src_ptr == '[')
+    {
+      /* Copy the line to the buffer */
+      if (!strncmp(++src_ptr, section_name, sect_len))
+      {
+	src_ptr+= sect_len;
+	/* Skip over whitespaces. They are allowed after section name */
+	for (; my_isspace(&my_charset_latin1, *src_ptr); src_ptr++)
+	{}
+
+	if (*src_ptr != ']')
+	  continue; /* Missing closing parenthesis. Assume this was no group */
+	
+        in_section= TRUE;
+        /* add option */
+        if (!remove_option)
+        {
+          tmp_ptr= strmov(tmp, option);
+          if (*option_value)
+          {
+	    *tmp_ptr++= '=';
+            tmp_ptr= strmov(tmp_ptr, option_value);
+          }
+          /* add a newline */
+	  strmov(tmp_ptr, NEWLINE);
+        }
+      }
+      else
+        in_section= FALSE; /* mark that this section is of no interest to us */
+    }
+  }
+  /* File ended. New option still remains to apply at the end */
+  if (tmp_ptr)
+  {
+    if (*(dst_ptr - 1) != '\n')
+      *dst_ptr++= '\n';
+    dst_ptr= strmov(dst_ptr, tmp);    
+  }
+
+  if (my_chsize(fileno(cnf_file), (my_off_t) (dst_ptr - file_buffer), 0,
+		MYF(MY_WME)) ||
+      my_fseek(cnf_file, 0, MY_SEEK_SET, MYF(0)) ||
+      my_fwrite(cnf_file, file_buffer, (uint) (dst_ptr - file_buffer),
+		MYF(MY_NABP)) ||
+      my_fclose(cnf_file, MYF(MY_WME)))
+     goto err;
+
+  my_free(file_buffer, MYF(0));
+
+  DBUG_RETURN(0);
+
+err:
+  my_free(file_buffer, MYF(0));
+malloc_err:
+  my_fclose(cnf_file, MYF(0));
+  DBUG_RETURN(1); /* out of resources */
+}