{"id":6823,"date":"2022-12-20T19:33:41","date_gmt":"2022-12-20T22:33:41","guid":{"rendered":"http:\/\/lode.uno\/linux-man\/index.php\/2022\/12\/20\/shadow-man3\/"},"modified":"2022-12-20T19:33:41","modified_gmt":"2022-12-20T22:33:41","slug":"shadow-man3","status":"publish","type":"post","link":"https:\/\/lode.uno\/linux-man\/2022\/12\/20\/shadow-man3\/","title":{"rendered":"SHADOW (man3)"},"content":{"rendered":"

SHADOW<\/h1>\n

NAME<\/a>
SYNTAX<\/a>
DESCRIPTION<\/a>
DESCRIPTION<\/a>
DIAGNOSTICS<\/a>
CAVEATS<\/a>
FILES<\/a>
SEE ALSO<\/a> <\/p>\n

\n

NAME <\/a> <\/h2>\n

shadow, getspnam \u2212 encrypted password file routines<\/p>\n

SYNTAX <\/a> <\/h2>\n

#include <\/i><\/p>\n

struct spwd *getspent();<\/i><\/p>\n

struct spwd *getspnam(char *name);<\/i><\/p>\n

void setspent();<\/i><\/p>\n

void endspent();<\/i><\/p>\n

struct spwd *fgetspent(FILE *fp);<\/i><\/p>\n

struct spwd *sgetspent(char *cp);<\/i><\/p>\n

int putspent(struct spwd *p, FILE *fp);<\/i><\/p>\n

int lckpwdf();<\/i><\/p>\n

int ulckpwdf();<\/i><\/p>\n

DESCRIPTION <\/a> <\/h2>\n

shadow<\/i> manipulates the contents of the shadow password file, \/etc\/shadow. The structure in the #include<\/i> file is:<\/p>\n

struct spwd {<\/p>\n\n\n

char<\/p>\n

\n\n\n\n\n\n\n\n
<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n <\/td>\n\n

*sp_namp; \/bin \/boot \/dead.letter \/dev \/etc \/home \/initrd \/lib \/lib64 \/lost+found \/media \/mnt \/opt \/proc \/release-notes.html \/release-notes.txt \/root \/run \/sbin \/srv \/sys \/tmp \/usr \/var user login name bodies\/ usr\/
char<\/p>\n<\/td>\n<\/tr>\n

<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n <\/td>\n\n

*sp_pwdp; \/bin \/boot \/dead.letter \/dev \/etc \/home \/initrd \/lib \/lib64 \/lost+found \/media \/mnt \/opt \/proc \/release-notes.html \/release-notes.txt \/root \/run \/sbin \/srv \/sys \/tmp \/usr \/var encrypted password bodies\/ usr\/
long int<\/p>\n<\/td>\n<\/tr>\n

<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n <\/td>\n\n

sp_lstchg; \/bin \/boot \/dead.letter \/dev \/etc \/home \/initrd \/lib \/lib64 \/lost+found \/media \/mnt \/opt \/proc \/release-notes.html \/release-notes.txt \/root \/run \/sbin \/srv \/sys \/tmp \/usr \/var last password change bodies\/ usr\/
long int<\/p>\n<\/td>\n<\/tr>\n

<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n <\/td>\n\n

sp_min; \/bin \/boot \/dead.letter \/dev \/etc \/home \/initrd \/lib \/lib64 \/lost+found \/media \/mnt \/opt \/proc \/release-notes.html \/release-notes.txt \/root \/run \/sbin \/srv \/sys \/tmp \/usr \/var days until change allowed. bodies\/ usr\/
long int<\/p>\n<\/td>\n<\/tr>\n

<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n <\/td>\n\n

sp_max; \/bin \/boot \/dead.letter \/dev \/etc \/home \/initrd \/lib \/lib64 \/lost+found \/media \/mnt \/opt \/proc \/release-notes.html \/release-notes.txt \/root \/run \/sbin \/srv \/sys \/tmp \/usr \/var days before change required bodies\/ usr\/
long int<\/p>\n<\/td>\n<\/tr>\n

<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n <\/td>\n\n

sp_warn; \/bin \/boot \/dead.letter \/dev \/etc \/home \/initrd \/lib \/lib64 \/lost+found \/media \/mnt \/opt \/proc \/release-notes.html \/release-notes.txt \/root \/run \/sbin \/srv \/sys \/tmp \/usr \/var days warning for expiration bodies\/ usr\/
long int<\/p>\n<\/td>\n<\/tr>\n

<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n <\/td>\n\n

sp_inact; \/bin \/boot \/dead.letter \/dev \/etc \/home \/initrd \/lib \/lib64 \/lost+found \/media \/mnt \/opt \/proc \/release-notes.html \/release-notes.txt \/root \/run \/sbin \/srv \/sys \/tmp \/usr \/var days before account inactive bodies\/ usr\/
long int<\/p>\n<\/td>\n<\/tr>\n

<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n <\/td>\n\n

sp_expire; \/bin \/boot \/dead.letter \/dev \/etc \/home \/initrd \/lib \/lib64 \/lost+found \/media \/mnt \/opt \/proc \/release-notes.html \/release-notes.txt \/root \/run \/sbin \/srv \/sys \/tmp \/usr \/var date when account expires bodies\/ usr\/
unsigned long int<\/p>\n<\/td>\n<\/tr>\n

<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n\n

sp_flag; \/bin \/boot \/dead.letter \/dev \/etc \/home \/initrd \/lib \/lib64 \/lost+found \/media \/mnt \/opt \/proc \/release-notes.html \/release-notes.txt \/root \/run \/sbin \/srv \/sys \/tmp \/usr \/var reserved for future use *\/<\/p>\n<\/td>\n<\/tr>\n<\/table>\n

}<\/p>\n

The meanings of each field are:<\/p>\n

\u2022 sp_namp \u2212 pointer to null\u2212terminated user name<\/p>\n

\u2022 sp_pwdp \u2212 pointer to null\u2212terminated password<\/p>\n

\u2022 sp_lstchg \u2212 days since Jan 1, 1970 password was last changed<\/p>\n

\u2022 sp_min \u2212 days before which password may not be changed<\/p>\n

\u2022 sp_max \u2212 days after which password must be changed<\/p>\n

\u2022 sp_warn \u2212 days before password is to expire that user is warned of pending password expiration<\/p>\n

\u2022 sp_inact \u2212 days after password expires that account is considered inactive and disabled<\/p>\n

\u2022 sp_expire \u2212 days since Jan 1, 1970 when account will be disabled<\/p>\n

\u2022 sp_flag \u2212 reserved for future use<\/p>\n

DESCRIPTION <\/a> <\/h2>\n

getspent<\/i>, getspname<\/i>, fgetspent<\/i>, and sgetspent<\/i> each return a pointer to a struct spwd<\/i>. getspent<\/i> returns the next entry from the file, and fgetspent<\/i> returns the next entry from the given stream, which is assumed to be a file of the proper format. sgetspent<\/i> returns a pointer to a struct spwd<\/i> using the provided string as input. getspnam<\/i> searches from the current position in the file for an entry matching name<\/i>.<\/p>\n

setspent<\/i> and endspent<\/i> may be used to begin and end, respectively, access to the shadow password file.<\/p>\n

The lckpwdf<\/i> and ulckpwdf<\/i> routines should be used to insure exclusive access to the \/etc\/shadow file. lckpwdf<\/i> attempts to acquire a lock using pw_lock<\/i> for up to 15 seconds. It continues by attempting to acquire a second lock using spw_lock<\/i> for the remainder of the initial 15 seconds. Should either attempt fail after a total of 15 seconds, lckpwdf<\/i> returns \u22121. When both locks are acquired 0 is returned.<\/p>\n

DIAGNOSTICS <\/a> <\/h2>\n

Routines return NULL if no more entries are available or if an error occurs during processing. Routines which have int<\/i> as the return value return 0 for success and \u22121 for failure.<\/p>\n

CAVEATS <\/a> <\/h2>\n

These routines may only be used by the superuser as access to the shadow password file is restricted.<\/p>\n

FILES <\/a> <\/h2>\n

\/etc\/shadow<\/p>\n

Secure user account information.<\/p>\n

SEE ALSO <\/a> <\/h2>\n

getpwent<\/b>(3), shadow<\/b>(5).<\/p>\n

\n","protected":false},"excerpt":{"rendered":"

shadow, getspnam \u2212 encrypted password file routines <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2536],"tags":[2538,3007,1323],"class_list":["post-6823","post","type-post","status-publish","format-standard","hentry","category-3-llamadas-de-bibliotecas","tag-2538","tag-man3","tag-shadow"],"gutentor_comment":0,"_links":{"self":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/posts\/6823","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/comments?post=6823"}],"version-history":[{"count":0,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/posts\/6823\/revisions"}],"wp:attachment":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/media?parent=6823"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/categories?post=6823"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/tags?post=6823"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}