您可以使用 getpwnam 以获得指向具有 pw_uid 成员的 struct passwd 结构的指针.示例程序:

You can use getpwnam to get a pointer to a struct passwd structure, which has pw_uid member. Example program:

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <pwd.h>

int main(int argc, char *argv[])
{
    const char *name = "root";
    struct passwd *p;
    if (argc > 1) {
        name = argv[1];
    }
    if ((p = getpwnam(name)) == NULL) {
        perror(name);
        return EXIT_FAILURE;
    }
    printf("%d\n", (int) p->pw_uid);
    return EXIT_SUCCESS;
}

如果要重入函数，请查看 getpwnam_r .

If you want a re-entrant function, look into getpwnam_r.