diff options
| author | Craig Jennings <c@cjennings.net> | 2024-04-07 13:41:34 -0500 |
|---|---|---|
| committer | Craig Jennings <c@cjennings.net> | 2024-04-07 13:41:34 -0500 |
| commit | 754bbf7a25a8dda49b5d08ef0d0443bbf5af0e36 (patch) | |
| tree | f1190704f78f04a2b0b4c977d20fe96a828377f1 /devdocs/c/io%2Ffeof.html | |
new repository
Diffstat (limited to 'devdocs/c/io%2Ffeof.html')
| -rw-r--r-- | devdocs/c/io%2Ffeof.html | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/devdocs/c/io%2Ffeof.html b/devdocs/c/io%2Ffeof.html new file mode 100644 index 00000000..088f217b --- /dev/null +++ b/devdocs/c/io%2Ffeof.html @@ -0,0 +1,56 @@ + <h1 id="firstHeading" class="firstHeading">feof</h1> <table class="t-dcl-begin"> <tr class="t-dsc-header"> <th> Defined in header <code><stdio.h></code> </th> <th> </th> <th> </th> </tr> <tr class="t-dcl"> <td class="t-dcl-nopad"> <pre data-language="c">int feof( FILE *stream );</pre> +</td> <td class="t-dcl-nopad"> </td> <td class="t-dcl-nopad"> </td> </tr> </table> <p>Checks if the end of the given file stream has been reached.</p> +<h3 id="Parameters"> Parameters</h3> <table class="t-par-begin"> <tr class="t-par"> <td> stream </td> <td> - </td> <td> the file stream to check </td> +</tr> +</table> <h3 id="Return_value"> Return value</h3> <p>nonzero value if the end of the stream has been reached, otherwise <code>0</code></p> +<h3 id="Notes"> Notes</h3> <p>This function only reports the stream state as reported by the most recent I/O operation, it does not examine the associated data source. For example, if the most recent I/O was a <code><a href="fgetc" title="c/io/fgetc">fgetc</a></code>, which returned the last byte of a file, <code>feof</code> returns zero. The next <code><a href="fgetc" title="c/io/fgetc">fgetc</a></code> fails and changes the stream state to <i>end-of-file</i>. Only then <code>feof</code> returns non-zero.</p> +<p>In typical usage, input stream processing stops on any error; <code>feof</code> and <code><a href="ferror" title="c/io/ferror">ferror</a></code> are then used to distinguish between different error conditions.</p> +<h3 id="Example"> Example</h3> <div class="t-example"> <div class="c source-c"><pre data-language="c">#include <stdio.h> +#include <stdlib.h> + +int main(void) +{ + const char* fname = "/tmp/unique_name.txt"; // or tmpnam(NULL); + int is_ok = EXIT_FAILURE; + + FILE* fp = fopen(fname, "w+"); + if (!fp) { + perror("File opening failed"); + return is_ok; + } + fputs("Hello, world!\n", fp); + rewind(fp); + + int c; // note: int, not char, required to handle EOF + while ((c = fgetc(fp)) != EOF) // standard C I/O file reading loop + putchar(c); + + if (ferror(fp)) + puts("I/O error when reading"); + else if (feof(fp)) { + puts("End of file is reached successfully"); + is_ok = EXIT_SUCCESS; + } + + fclose(fp); + remove(fname); + return is_ok; +}</pre></div> <p>Possible output:</p> +<div class="text source-text"><pre data-language="c">Hello, world! +End of file is reached successfully</pre></div> </div> <h3 id="References"> References</h3> <ul> +<li> C11 standard (ISO/IEC 9899:2011): </li> +<ul><li> 7.21.10.2 The feof function (p: 339) </li></ul> +<li> C99 standard (ISO/IEC 9899:1999): </li> +<ul><li> 7.19.10.2 The feof function (p: 305) </li></ul> +<li> C89/C90 standard (ISO/IEC 9899:1990): </li> +<ul><li> 4.9.10.2 The feof function </li></ul> +</ul> <h3 id="See_also"> See also</h3> <table class="t-dsc-begin"> <tr class="t-dsc"> <td> <div><a href="clearerr" title="c/io/clearerr"> <span class="t-lines"><span>clearerr</span></span></a></div> </td> <td> clears errors <br> <span class="t-mark">(function)</span> </td> +</tr> <tr class="t-dsc"> <td> <div><a href="perror" title="c/io/perror"> <span class="t-lines"><span>perror</span></span></a></div> </td> <td> displays a character string corresponding of the current error to <code><a href="std_streams" title="c/io/std streams">stderr</a></code> <br> <span class="t-mark">(function)</span> </td> +</tr> <tr class="t-dsc"> <td> <div><a href="ferror" title="c/io/ferror"> <span class="t-lines"><span>ferror</span></span></a></div> </td> <td> checks for a file error <br> <span class="t-mark">(function)</span> </td> +</tr> <tr class="t-dsc"> <td colspan="2"> <span><a href="https://en.cppreference.com/w/cpp/io/c/feof" title="cpp/io/c/feof">C++ documentation</a></span> for <code>feof</code> </td> +</tr> </table> <div class="_attribution"> + <p class="_attribution-p"> + © cppreference.com<br>Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.<br> + <a href="https://en.cppreference.com/w/c/io/feof" class="_attribution-link">https://en.cppreference.com/w/c/io/feof</a> + </p> +</div> |
