Linux系统口令文件定义在头文件
struct passwd应包含以下成员：
char *pw_name User's login name. uid_t pw_uid Numerical user ID. gid_t pw_gid Numerical group ID. char *pw_dir Initial working directory. char *pw_shell Program to use as shell.
读口令文件应该用到的函数：
// The endpwent() function is used to close the password database after all processing has been performed. void endpwent(void); // The getpwent() function returns a pointer to a structure containing the broken-out fields of a record // from the password database (e.g., the local password file /etc/passwd, NIS, and LDAP). The first time // getpwent() is called, it returns the first entry; thereafter, it returns successive entries. struct passwd *getpwent(void); // The setpwent() function rewinds to the beginning of the password database. void setpwent(void);
示例代码：
#include <pwd.h>
#include <stdio.h>
int main(void)
{
struct passwd *pwd;
setpwent();
while((pwd = getpwent()) != NULL)
{
printf("%s\t%d\t%d\t%s\t%s\n", pwd->pw_name, pwd->pw_uid,
pwd->pw_gid, pwd->pw_dir, pwd->pw_shell);
}
endpwent();
return 0;
}
运行结果：
[ycxie@fedora Workspace]$ gcc printpwent.c -o printpwent -Wall [ycxie@fedora Workspace]$ ./printpwent gluster 996 991 /run/gluster /sbin/nologin tcpdump 72 72 / /sbin/nologin nm-openconnect 988 982 / /sbin/nologin avahi 70 70 /var/run/avahi-daemon /sbin/nologin sshd 74 74 /var/empty/sshd /sbin/nologin rpcuser 29 29 /var/lib/nfs /sbin/nologin openvpn 994 989 /etc/openvpn /sbin/nologin bin 1 1 /bin /sbin/nologin games 12 100 /usr/games /sbin/nologin systemd-network 192 192 / /sbin/nologin gdm 42 42 /var/lib/gdm /sbin/nologin ycxie 1000 1000 /home/ycxie /bin/bash pipewire 993 987 /var/run/pipewire /sbin/nologin setroubleshoot 987 980 /var/lib/setroubleshoot /sbin/nologin usbmuxd 113 113 / /sbin/nologin daemon 2 2 /sbin /sbin/nologin dnsmasq 978 978 /var/lib/dnsmasq /sbin/nologin ftp 14 50 /var/ftp /sbin/nologin systemd-resolve 193 193 / /sbin/nologin adm 3 4 /var/adm /sbin/nologin saslauth 990 76 /run/saslauthd /sbin/nologin qemu 107 107 / /sbin/nologin tss 59 59 /dev/null /sbin/nologin gnome-initial-setup 986 979 /run/gnome-initial-setup/ /sbin/nologin nobody 99 99 / /sbin/nologin geoclue 992 986 /var/lib/geoclue /sbin/nologin mail 8 12 /var/spool/mail /sbin/nologin rpc 32 32 /var/lib/rpcbind /sbin/nologin polkitd 997 996 / /sbin/nologin colord 991 984 /var/lib/colord /sbin/nologin pulse 171 171 /var/run/pulse /sbin/nologin systemd-coredump 999 998 / /sbin/nologin rtkit 172 172 /proc /sbin/nologin apache 48 48 /usr/share/httpd /sbin/nologin lp 4 7 /var/spool/lpd /sbin/nologin chrony 995 990 /var/lib/chrony /sbin/nologin dbus 81 81 / /sbin/nologin radvd 75 75 / /sbin/nologin systemd-timesync 998 997 / /sbin/nologin nm-openvpn 989 983 / /sbin/nologin abrt 173 173 /etc/abrt /sbin/nologin root 0 0 /root /bin/bash bin 1 1 /bin /sbin/nologin daemon 2 2 /sbin /sbin/nologin adm 3 4 /var/adm /sbin/nologin lp 4 7 /var/spool/lpd /sbin/nologin sync 5 0 /sbin /bin/sync shutdown 6 0 /sbin /sbin/shutdown halt 7 0 /sbin /sbin/halt mail 8 12 /var/spool/mail /sbin/nologin operator 11 0 /root /sbin/nologin games 12 100 /usr/games /sbin/nologin ftp 14 50 /var/ftp /sbin/nologin nobody 99 99 / /sbin/nologin apache 48 48 /usr/share/httpd /sbin/nologin systemd-coredump 999 998 / /sbin/nologin systemd-timesync 998 997 / /sbin/nologin systemd-network 192 192 / /sbin/nologin systemd-resolve 193 193 / /sbin/nologin dbus 81 81 / /sbin/nologin polkitd 997 996 / /sbin/nologin qemu 107 107 / /sbin/nologin rtkit 172 172 /proc /sbin/nologin pulse 171 171 /var/run/pulse /sbin/nologin gluster 996 991 /run/gluster /sbin/nologin avahi 70 70 /var/run/avahi-daemon /sbin/nologin chrony 995 990 /var/lib/chrony /sbin/nologin usbmuxd 113 113 / /sbin/nologin openvpn 994 989 /etc/openvpn /sbin/nologin radvd 75 75 / /sbin/nologin pipewire 993 987 /var/run/pipewire /sbin/nologin geoclue 992 986 /var/lib/geoclue /sbin/nologin rpc 32 32 /var/lib/rpcbind /sbin/nologin colord 991 984 /var/lib/colord /sbin/nologin saslauth 990 76 /run/saslauthd /sbin/nologin nm-openvpn 989 983 / /sbin/nologin nm-openconnect 988 982 / /sbin/nologin gdm 42 42 /var/lib/gdm /sbin/nologin abrt 173 173 /etc/abrt /sbin/nologin setroubleshoot 987 980 /var/lib/setroubleshoot /sbin/nologin rpcuser 29 29 /var/lib/nfs /sbin/nologin gnome-initial-setup 986 979 /run/gnome-initial-setup/ /sbin/nologin sshd 74 74 /var/empty/sshd /sbin/nologin tss 59 59 /dev/null /sbin/nologin tcpdump 72 72 / /sbin/nologin ycxie 1000 1000 /home/ycxie /bin/bash dnsmasq 978 978 /var/lib/dnsmasq /sbin/nologin