_getc_nolock, _getwc_nolock

Reads a character from a stream without locking.

Syntax

int _getc_nolock(
   FILE *stream
);
wint_t _getwc_nolock(
   FILE *stream
);

Parameters

stream
Input stream.

Return value

See getc, getwc.

Remarks

These functions are identical to getc and getwc except that they don't lock the calling thread. They might be faster because they don't 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.

By default, this function's global state is scoped to the application. To change this behavior, see Global state in the CRT.

Generic-text routine mappings

Requirements

For more compatibility information, see Compatibility.

Example

// crt_getc_nolock.c
// Use getc to read a line from a file.

#include <stdio.h>

int main()
{
    char buffer[81];
    int i, ch;
    FILE* fp;

    // Read a single line from the file "crt_getc_nolock.txt".
    fopen_s(&fp, "crt_getc_nolock.txt", "r");
    if (!fp)
    {
       printf("Failed to open file crt_getc_nolock.txt.\n");
       exit(1);
    }

    for (i = 0; (i < 80) && ((ch = getc(fp)) != EOF)
                         && (ch != '\n'); i++)
    {
        buffer[i] = (char) ch;
    }

    // Terminate string with a null character
    buffer[i] = '\0';
    printf( "Input was: %s\n", buffer);

    fclose(fp);
}

Input: crt_getc_nolock.txt

Line the first.
Line the second.

Output

Input was: Line the first.

See also

Stream I/O
fgetc, fgetwc
_getch, _getwch
putc, putwc
ungetc, ungetwc