O nás     Inzerce     KontaktSpolehlivé informace o IT již od roku 2011
Hledat
Nepřehlédněte: 2. kolo: Pozoruhodné IT produkty 2020
Správa dokumentů
Digitální transformace
Informační systémy
Hlavní rubriky: Informační systémy, Mobilní technologie, Datová centra, Sítě, IT bezpečnost, Software, Hardware, Zkušenosti a názory, Speciály

Pozoruhodné IT produkty 2020
E-knihy o IT zdarma
Odborné IT konference BusinessIT
Manuál Linux
[Linux manuál]

tmpnam: vytvořit název dočasného souboru

Originální popis anglicky: tmpnam - create a name for a temporary file

Návod, kniha: POSIX Programmer's Manual

STRUČNĚ

#include <stdio.h>
 
 
char *tmpnam(char * s);
 

POPIS / INSTRUKCE

The tmpnam() function shall generate a string that is a valid filename and that is not the same as the name of an existing file. The function is potentially capable of generating {TMP_MAX} different strings, but any or all of them may already be in use by existing files and thus not be suitable return values.
The tmpnam() function generates a different string each time it is called from the same process, up to {TMP_MAX} times. If it is called more than {TMP_MAX} times, the behavior is implementation-defined.
The implementation shall behave as if no function defined in this volume of IEEE Std 1003.1-2001 calls tmpnam().
If the application uses any of the functions guaranteed to be available if either _POSIX_THREAD_SAFE_FUNCTIONS or _POSIX_THREADS is defined, the application shall ensure that the tmpnam() function is called with a non-NULL parameter.

NÁVRATOVÁ HODNOTA

Upon successful completion, tmpnam() shall return a pointer to a string. If no suitable string can be generated, the tmpnam() function shall return a null pointer.
If the argument s is a null pointer, tmpnam() shall leave its result in an internal static object and return a pointer to that object. Subsequent calls to tmpnam() may modify the same object. If the argument s is not a null pointer, it is presumed to point to an array of at least L_tmpnam chars; tmpnam() shall write its result in that array and shall return the argument as its value.

CHYBY / ERRORY

No errors are defined.
The following sections are informative.

PŘÍKLADY POUŽITÍ

Generating a Filename

The following example generates a unique filename and stores it in the array pointed to by ptr.
 
#include <stdio.h> ... char filename[L_tmpnam+1]; char *ptr;
 
ptr = tmpnam(filename);

APPLICATION USAGE

This function only creates filenames. It is the application's responsibility to create and remove the files.
Between the time a pathname is created and the file is opened, it is possible for some other process to create a file with the same name. Applications may find tmpfile() more useful.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SOUVISEJÍCÍ

fopen() , open() , tempnam() , tmpfile() , unlink() , the Base Definitions volume of IEEE Std 1003.1-2001, <stdio.h> Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .
2003 IEEE/The Open Group
©2011-2020 BusinessIT.cz, ISSN 1805-0522 | Názvy použité v textech mohou být ochrannými známkami příslušných vlastníků.
Provozovatel: Bispiral, s.r.o., kontakt: BusinessIT(at)Bispiral.com | Inzerce: Best Online Media, s.r.o., zuzana@online-media.cz
O vydavateli | Pravidla webu BusinessIT.cz a ochrana soukromí | pg(8463)