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%2Ftmpnam.html | 83 ---------------------------------------------- 1 file changed, 83 deletions(-) delete mode 100644 devdocs/c/io%2Ftmpnam.html (limited to 'devdocs/c/io%2Ftmpnam.html') diff --git a/devdocs/c/io%2Ftmpnam.html b/devdocs/c/io%2Ftmpnam.html deleted file mode 100644 index 0285bdf5..00000000 --- a/devdocs/c/io%2Ftmpnam.html +++ /dev/null @@ -1,83 +0,0 @@ -

tmpnam, tmpnam_s

Defined in header <stdio.h> 
char *tmpnam( char *filename );
-		 (1) 
errno_t tmpnam_s(char *filename_s, rsize_t maxsize);
-		 (2) (since C11) 
#define TMP_MAX        /*unspecified*/
-		 
#define TMP_MAX_S      /*unspecified*/
-		 (since C11) 
#define L_tmpnam       /*unspecified*/
-		 
#define L_tmpnam_s     /*unspecified*/
-		 (since C11)
-1) Creates a unique valid file name (no longer than L_tmpnam in length) and stores it in character string pointed to by filename. The function is capable of generating up to TMP_MAX of unique filenames, but some or all of them may be in use in the filesystem and thus not suitable return values.
-2) Same as (1), except that up to TMP_MAX_S names may be generated, no longer than L_tmpnam_s in length, and the following errors are detected at runtime and call the currently installed constraint handler function:
-
-
    -
  • filename_s is a null pointer
    • -
  • maxsize is greater than RSIZE_MAX
    • -
  • maxsize is less than the generated file name string
    • -
-
As with all bounds-checked functions, tmpnam_s only guaranteed to be available if __STDC_LIB_EXT1__ is defined by the implementation and if the user defines __STDC_WANT_LIB_EXT1__ to the integer constant 1 before including <stdio.h>.
-
-

tmpnam and tmpnam_s modify static state (which may be shared between these functions) and are not required to be thread-safe.

-

Parameters

- - - -
filename - pointer to the character array capable of holding at least L_tmpnam bytes, to be used as a result buffer. If null pointer is passed, a pointer to an internal static buffer is returned.
filename_s - pointer to the character array capable of holding at least L_tmpnam_s bytes, to be used as a result buffer.
maxsize - maximum number of characters the function is allowed to write (typically the size of the filename_s array).

Return value

-1) filename if filename was not a null pointer. Otherwise a pointer to an internal static buffer is returned. If no suitable filename can be generated, null pointer is returned.
-2) Returns zero and writes the file name to filename_s on success. On error, returns non-zero and writes the null character to filename_s[0] (only if filename_s is not null and maxsize is not zero and is not greater than RSIZE_MAX).

Notes

Although the names generated by tmpnam are difficult to guess, it is possible that a file with that name is created by another process between the moment tmpnam returns and the moment this program attempts to use the returned name to create a file. The standard function tmpfile and the POSIX function mkstemp do not have this problem (creating a unique directory using only the standard C library still requires the use of tmpnam).

-

POSIX systems additionally define the similarly named function tempnam, which offers the choice of a directory (which defaults to the optionally defined macro P_tmpdir).

-

Example

#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
- 
-int main(void)
-{
-    // Note, the compiler/linker may issue a security warning, e.g. GCC:
-    // "warning: the use of `tmpnam' is dangerous, better use `mkstemp'"
-    char* name1 = tmpnam(NULL);
-    printf("temporary file name: %s\n", name1);
- 
-    char name2[L_tmpnam];
-    if (tmpnam(name2))
-        printf("temporary file name: %s\n", name2);
- 
-    // POSIX offers mkstemp. The following declaration might be
-    // necessary as mkstemp is absent in the standard C <stdlib.h>.
-    int mkstemp(char*);
- 
-    char name3[] = "/tmp/fileXXXXXX"; // at least six 'X' required ^_^
-    int file_descriptor = mkstemp(name3);
-    if (file_descriptor != -1)
-        printf("temporary file name: %s\n", name3);
-    else
-        perror("mkstemp");
-}

Possible output:

-
temporary file name: /tmp/file90dLlR
-temporary file name: /tmp/fileY9LWAg
-temporary file name: /tmp/filexgv8PF

References

See also

- -
-
(C11)
 returns a pointer to a temporary file
(function)
C++ documentation for tmpnam
-

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

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