#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int main(int argc, char *argv[])
{
char szBuf[512];
char szName[512];
FILE *f = fopen("/etc/passwd","r");
memset(szBuf, 0, sizeof(szBuf));
int i;
while(fgets(szBuf, sizeof(szBuf),f) != NULL)
{
memset(szName, 0, sizeof(szName));
for(i = 0; i< sizeof(szBuf); i++)
{
if(':' == szBuf[i])
{
break;
}
szName[i] = szBuf[i];
}
printf("%s
", szName);
memset(szBuf, 0, sizeof(szBuf));
}
fclose(f);
}
运行结果：
huangcheng@ubuntu:~$ ./a.out root daemon bin sys sync games man lp mail news uucp proxy www-data backup list irc gnats nobody libuuid syslog messagebus avahi-autoipd avahi couchdb speech-dispatcher usbmux haldaemon kernoops pulse rtkit saned hplip gdm huangcheng tftp statd sshd samba ftp