_fgetc_nolock, _fgetwc_nolock

 

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Reads a character from a stream without locking the thread.

int _fgetc_nolock(   
   FILE *stream   
);  
wint_t _fgetwc_nolock(   
   FILE *stream   
);  

Parameters

stream
Pointer to the FILE structure.

Seefgetc, fgetwc.

_fgetc_nolock and _fgetwc_nolock are identical to fgetc and fgetwc, respectively, except that they are not protected from interference by other threads. They might be faster because they do not incur the overhead of locking out other threads. Use these functions only in thread-safe contexts such as single-threaded applications or where the calling scope already handles thread isolation.

Generic-Text Routine Mappings

Tchar.h routine_UNICODE and _MBCS not defined_MBCS defined_UNICODE defined
_fgettc_nolock_fgetc_nolock_fgetc_nolock_fgetwc_nolock
FunctionRequired header
_fgetc_nolock<stdio.h>
_fgetwc_nolock<stdio.h> or <wchar.h>

For more compatibility information, see Compatibility in the Introduction.

// crt_fgetc_nolock.c  
// This program uses getc to read the first  
// 80 input characters (or until the end of input)  
// and place them into a string named buffer.  
  
#include <stdio.h>  
#include <stdlib.h>  
  
int main( void )  
{  
   FILE *stream;  
   char buffer[81];  
   int  i, ch;  
  
   // Open file to read line from:   
   if( fopen_s( &stream, "crt_fgetc_nolock.txt", "r" ) != 0 )  
      exit( 0 );  
  
   // Read in first 80 characters and place them in "buffer":  
   ch = fgetc( stream );  
   for( i=0; (i < 80 ) && ( feof( stream ) == 0 ); i++ )  
   {  
      buffer[i] = (char)ch;  
      ch = _fgetc_nolock( stream );  
   }  
  
   // Add null to end string   
   buffer[i] = '\0';  
   printf( "%s\n", buffer );  
   fclose( stream );  
}  

Line one.  
Line two.  

Output

Line one.  
Line two.  

Stream I/O
fputc, fputwc
getc, getwc

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