C fdopen with and without -ansi Post: 303024644

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Top Forums Programming C fdopen with and without -ansi Post 303024644 by migurus on Saturday 13th of October 2018 08:15:49 PM

10-13-2018

Registered User

C fdopen with and without -ansi

I have very little experience with gcc compilation under different environments, so please bear with me. I carried over 20 years old project into Ubuntu 18.04, it has old style K&R parameters, no function declarations to speak of, many functions without return are not declared void, and on and on...
I did a bit of cleanup and I realized that if I use -ansi then my compilation is almost 100% clean. But one simple routine complains about fdopen when I specify -ansi, without -ansi there is no complains.

Here is the code:

Code:

  $ cat f.c  
#include <stdio.h>  
#include <stdlib.h>   

FILE * my_tester(char *fname, int pnum) 
{   
  int    fd;   
  FILE *fp;      
    sprintf(fname, "/tmp/PRS.%05i.XXXXXX", pnum);         
    fd = mkstemp(fname);     
    if(fd < 0) 
    {    
         return(NULL); 
    }         
    if((fp = fdopen(fd, "w")) == NULL)     
    {         
        return(NULL);     
    }
     return(fp); 
}

Here is my compilation attempt:

Code:

  
$ cc -c -o f.o f.c  
$  
$ cc -ansi -c -o f.o f.c f.c:
 In function �my_tester': f.c:15:16: warning: assignment makes pointer from integer without a cast [-Wint-conversion]          if((fp = fdopen(fd, "w")) == NULL) 
$

I'd appreciate suggestions on what would be reasonable set of compiler flags. A simple C standards documentation covering those flags and those __USE_ macros would be much appreciated

Last edited by migurus; 10-13-2018 at 09:21 PM.. Reason: cut/paste did not work in Linux/Firefox, had to boot windows and make it readable in Chrome

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LEARN ABOUT CENTOS

tapset::ansi

tapset::ansi(3stap)													       tapset::ansi(3stap)

NAME

       tapset::ansi - systemtap ansi tapset

DESCRIPTION

       ansi_clear_screen
	      Move cursor to top left and clear screen.

	      See function::ansi_clear_screen(3stap)
	       for details.

       ansi_set_color
	      Set the ansi Select Graphic Rendition mode.

	      See function::ansi_set_color(3stap)
	       for details.

       ansi_set_color2
	      Set the ansi Select Graphic Rendition mode.

	      See function::ansi_set_color2(3stap)
	       for details.

       ansi_set_color3
	      Set the ansi Select Graphic Rendition mode.

	      See function::ansi_set_color3(3stap)
	       for details.

       ansi_reset_color
	      Resets Select Graphic Rendition mode.

	      See function::ansi_reset_color(3stap)
	       for details.

       ansi_new_line
	      Move cursor to new line.

	      See function::ansi_new_line(3stap)
	       for details.

       ansi_cursor_move
	      Move cursor to new coordinates.

	      See function::ansi_cursor_move(3stap)
	       for details.

       ansi_cursor_hide
	      Hides the cursor.

	      See function::ansi_cursor_hide(3stap)
	       for details.

       ansi_cursor_save
	      Saves the cursor position.

	      See function::ansi_cursor_save(3stap)
	       for details.

       ansi_cursor_restore
	      Restores a previously saved cursor position.

	      See function::ansi_cursor_restore(3stap)
	       for details.

       ansi_cursor_show
	      Shows the cursor.

	      See function::ansi_cursor_show(3stap)
	       for details.

SEE ALSO

	      function::ansi_clear_screen(3stap),	       function::ansi_set_color(3stap), 	   function::ansi_set_color2(3stap),
       function::ansi_set_color3(3stap),  function::ansi_reset_color(3stap),  function::ansi_new_line(3stap),  function::ansi_cursor_move(3stap),
       function::ansi_cursor_hide(3stap),	       function::ansi_cursor_save(3stap),	       function::ansi_cursor_restore(3stap),
       function::ansi_cursor_show(3stap),  stap(1), stapprobes(3stap)

IBM
									---						       tapset::ansi(3stap)