我正在尝试获取系统中所有用户(linux、fedora)的列表。
我听说功能:fgetpwent
是我完成任务所需要的。
可悲的是,我没有找到任何文档或如何使用此函数的示例。
如果有人能给我举个例子,那就太好了,提前谢谢。
最佳答案
不知道为什么我会用它:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <crypt.h>
#include <pwd.h>
#include <sys/types.h>
char *testentry = "testread";
static void read_etc_passwd (void) {
struct passwd *pwd_entry = NULL;
int found = 0;
setpwent(); // go to the top of /etc/passwd
while (!found && (pwd_entry = getpwent())){
if (0 == strcmp (testentry, pwd_entry->pw_name)){
found = 1;
}
}
if (found) {
printf ("name = %s\nhome = %s\n", pwd_entry->pw_name,
pwd_entry->pw_dir);
} else {
puts("could not find the entry you were looking for, or"
"some error occurred");
}
}
void change_etc_passwd (void){
struct passwd *pwd = NULL;
FILE *pwd_fd = NULL;
FILE *pwd_new = NULL;
int result = 0;
pwd_fd = fopen ("/etc/passwd", "r");
pwd_new = fopen ("/tmp/passwd.neu", "a");
// assuming everthing went fine (bad idea)
while (pwd = fgetpwent (pwd_fd)){
if (0 == strcmp (pwd->pw_name, testentry)){
pwd->pw_passwd = crypt ("new_pwd", "aa");
}
result = putpwent(pwd, pwd_new);
if (result < 0){
fprintf (stderr, "Failed to write entry, giving up\n");
exit (EXIT_FAILURE);
}
}
}
int main (void) {
/* handling of /etc/passwd */
read_etc_passwd ();
change_etc_passwd();
return 0;
}
添加错误处理,甚至可以在不中断的情况下工作;-)
关于c - 如何使用fgetpwent()?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/22556749/