From 82ba818ff456bcd6d56a06226e3f27e98fbb55c3 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Thu, 14 Aug 2025 22:58:58 -0500 Subject: removing all downloaded devdocs files --- devdocs/c/io%2Fftell.html | 77 ----------------------------------------------- 1 file changed, 77 deletions(-) delete mode 100644 devdocs/c/io%2Fftell.html (limited to 'devdocs/c/io%2Fftell.html') diff --git a/devdocs/c/io%2Fftell.html b/devdocs/c/io%2Fftell.html deleted file mode 100644 index c2696fdea..000000000 --- a/devdocs/c/io%2Fftell.html +++ /dev/null @@ -1,77 +0,0 @@ -

ftell

Defined in header <stdio.h> 
long ftell( FILE *stream );
-

Returns the file position indicator for the file stream stream.

-

If the stream is open in binary mode, the value obtained by this function is the number of bytes from the beginning of the file.

-

If the stream is open in text mode, the value returned by this function is unspecified and is only meaningful as the input to fseek().

-

Parameters

- -
stream - file stream to examine

Return value

File position indicator on success or -1L if failure occurs.

-

On error, the errno variable is set to implementation-defined positive value.

-

Example

-

Demonstrates ftell() with error checking. Writes then reads a few floating-point (FP) values to/from a file.

-
#include <stdio.h>
-#include <stdlib.h>
- 
-/* If the condition is not met then exit the program with error message. */
-void check(_Bool condition, const char* func, int line)
-{
-    if (condition)
-        return;
-    perror(func);
-    fprintf(stderr, "%s failed in file %s at line # %d\n", func, __FILE__, line - 1);
-    exit(EXIT_FAILURE);
-}
- 
-int main(void)
-{
-    /* Prepare an array of FP values. */
-    #define SIZE 5
-    double A[SIZE] = {1.1,2.,3.,4.,5.};
- 
-    /* Write array to a file. */
-    const char* fname = "/tmp/test.bin";
-    FILE* file = fopen(fname, "wb");
-    check(file != NULL, "fopen()", __LINE__);
- 
-    const int write_count = fwrite(A, sizeof(double), SIZE, file);
-    check(write_count == SIZE, "fwrite()", __LINE__);
- 
-    fclose(file);
- 
-    /* Read the FP values into array B. */
-    double B[SIZE];
-    file = fopen(fname, "rb");
-    check(file != NULL, "fopen()", __LINE__);
- 
-    long int pos = ftell(file); /* position indicator at start of file */
-    check(pos != -1L, "ftell()", __LINE__);
-    printf("pos: %ld\n", pos);
- 
-    const int read_count = fread(B, sizeof(double), 1, file); /* read one FP value */
-    check(read_count == 1, "fread()", __LINE__);
- 
-    pos = ftell(file); /* position indicator after reading one FP value */
-    check(pos != -1L, "ftell()", __LINE__);
-    printf("pos: %ld\n", pos);
-    printf("B[0]: %.1f\n", B[0]); /* print one FP value */
- 
-    return EXIT_SUCCESS;
-}

Possible output:

-
pos: 0
-pos: 8
-B[0]: 1.1

References

See also

- - - -
gets the file position indicator
(function)
moves the file position indicator to a specific location in a file
(function)
moves the file position indicator to a specific location in a file
(function)
C++ documentation for ftell
-

- © cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
- https://en.cppreference.com/w/c/io/ftell -

-
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