C語言 tmpnam()用法及代碼示例

tmpnam()函數是一個特殊函數，它在“stdio.h”頭文件中聲明。每次至少調用TMP_MAX名稱時，它都會生成一個不同的臨時文件名。在此，TMP_MAX表示tmpnam()函數可以產生的最大不同文件名數。如果它的調用次數超過了TMP_MAX次，則該行為取決於實現。此處，L_tmpnam定義了一個char數組保存tmpnam結果所需的大小。

用法:

char *tmpnam(char *str)
s: The character array to copy the file name.
It generates and returns a valid temporary 
filename which does not exist. 
If str is null then it simply returns the tmp file name.

// C program to generate random temporary file names. 
#include <stdio.h> 
int main(void) 
{ 
    // L_tmpnam declared in the stdio.h file. 
    // L_tmpnam define length of the generated file name. 
    char generate[L_tmpnam + 1]; // Add +1 for the null character. 
    tmpnam(generate); 
    puts(generate); 
    return 0; 
}

輸出：

The file names are dependent on running machine, which can be anything.
Example:/tmp/fileRTOA0m
         \s260.
         \s3ok.
         \s5gg. etc