在C中生成路径的最佳方法是什么？

#define GPIO_PATH_BASE      "/sys/class/gpio/gpio"
#define GPIO_PATH_DIRECTION "/direction"
#define GPIO_PATH_VALUE     "/value"

int open_gpio(const char * port)
{
    char *base_path  = asprintf("%s%s",GPIO_PATH_BASE,port);
    char *value_path = asprintf("%s%s",base_path,GPIO_PATH_value);
    char *dir_path   = asprintf("%s%s",GPIO_PATH_DIRECTION);
    //...do some work with these...or return them...
    //...should check for Failed alLOCATIOns,too...
}

如果你的系统不支持asprintf(),你可以用以下方法“伪造”它：

#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>

/* Should be in a header */
#ifndef HAVE_ASPRINTF
extern int asprintf(char **ret,const char *format,...);
extern int vasprintf(char **ret,va_list args);
#endif

#ifndef HAVE_ASPRINTF

int vasprintf(char **ret,va_list args)
{
    va_list copy;
    va_copy(copy,args);

    /* Make sure return pointer is determinate */
    *ret = 0;

    int count = vsnprintf(NULL,format,args);
    if (count >= 0)
    {
        char* buffer = malloc(count + 1);
        if (buffer != NULL)
        {
            count = vsnprintf(buffer,count + 1,copy);
            if (count < 0)
            {
                free(buffer);
                buffer = 0;
            }
            *ret = buffer;
        }
    }

    va_end(copy);

    return count;
}

int asprintf(char **ret,...)
{
    va_list args;
    va_start(args,format);
    int count = vasprintf(ret,args);
    va_end(args);
    return(count);
}

#endif /* HAVE_ASPRINTF */