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AC_CHECK_FUNCS(getlogin)

AC_CHECK_FUNCS(getlogin_r)

AC_CHECK_FUNCS(getpwnam)

AC_CHECK_FUNCS(getpwuid)

AC_CHECK_FUNCS(getpwuid_r)

/* We'll look up the user's default home dir in the password db by

* login name, if possible, and failing that will fall back to looking

* the information up by uid (as would be needed for processes that

* are not a descendant of login(1) or a work-alike).

*

* While the lookup by uid is more likely to succeed (since we always

* have a uid, but may or may not have a login name), we prefer first

* looking up by name to accommodate the possibility of multiple login

* names (each with its own record in the password database, so each

* with a potentially different home directory) being mapped to the

* same uid (as explicitly allowed for by POSIX; see getlogin(3posix)).

*/

VALUE login_name = rb_getlogin();

# if !defined(HAVE_GETPWUID_R) && !defined(HAVE_GETPWUID)

/* This is a corner case, but for backward compatibility reasons we

* want to emit this error if neither the lookup by login name nor

* lookup by getuid() has a chance of succeeding.

*/

if (NIL_P(login_name)) {

rb_raise(rb_eArgError, "couldn't find login name -- expanding `~'");

}

# endif

VALUE pw_dir = rb_getpwdirnam_for_login(login_name);

if (NIL_P(pw_dir)) {

pw_dir = rb_getpwdiruid();

if (NIL_P(pw_dir)) {

rb_raise(rb_eArgError, "couldn't find home for uid `%ld'", (long)getuid());

}

}

/* found it */

copy_home_path(result, RSTRING_PTR(pw_dir));

rb_str_resize(pw_dir, 0);

return result;

#ifdef HAVE_PWD_H

VALUE rb_getlogin(void);

VALUE rb_getpwdirnam_for_login(VALUE login); /* read as: "get pwd db home dir by username for login" */

VALUE rb_getpwdiruid(void); /* read as: "get pwd db home dir for getuid()" */

#endif

#if defined(HAVE_UNISTD_H)

# if defined(HAVE_GETLOGIN_R)

# define USE_GETLOGIN_R 1

# define GETLOGIN_R_SIZE_DEFAULT 0x100

# define GETLOGIN_R_SIZE_LIMIT 0x1000

# if defined(_SC_LOGIN_NAME_MAX)

# define GETLOGIN_R_SIZE_INIT sysconf(_SC_LOGIN_NAME_MAX)

# else

# define GETLOGIN_R_SIZE_INIT GETLOGIN_R_SIZE_DEFAULT

# endif

# elif defined(HAVE_GETLOGIN)

# define USE_GETLOGIN 1

# endif

#endif

# if defined(HAVE_GETPWUID_R)

# define USE_GETPWUID_R 1

# elif defined(HAVE_GETPWUID)

# define USE_GETPWUID 1

# endif

# if defined(HAVE_GETPWNAM_R)

# elif defined(HAVE_GETPWNAM)

# define USE_GETPWNAM 1

# endif

# if defined(HAVE_GETPWNAM_R) || defined(HAVE_GETPWUID_R)

# if defined(_SC_GETPW_R_SIZE_MAX)

# define GETPW_R_SIZE_INIT sysconf(_SC_GETPW_R_SIZE_MAX)

# else

# define GETPW_R_SIZE_INIT GETPW_R_SIZE_DEFAULT

# endif

#if defined(HAVE_PWD_H)

/**

* Best-effort attempt to obtain the name of the login user, if any,

* associated with the process. Processes not descended from login(1) (or

* similar) may not have a logged-in user; returns Qnil in that case.

*/

VALUE

rb_getlogin(void)

{

#if ( !defined(USE_GETLOGIN_R) && !defined(USE_GETLOGIN) )

return Qnil;

#else

char MAYBE_UNUSED(*login) = NULL;

# ifdef USE_GETLOGIN_R

long loginsize = GETLOGIN_R_SIZE_INIT; /* maybe -1 */

if (loginsize < 0)

loginsize = GETLOGIN_R_SIZE_DEFAULT;

VALUE maybe_result = rb_str_buf_new(loginsize);

login = RSTRING_PTR(maybe_result);

loginsize = rb_str_capacity(maybe_result);

rb_str_set_len(maybe_result, loginsize);

int gle;

errno = 0;

while ((gle = getlogin_r(login, loginsize)) != 0) {

if (gle == ENOTTY || gle == ENXIO || gle == ENOENT) {

rb_str_resize(maybe_result, 0);

return Qnil;

}

if (gle != ERANGE || loginsize >= GETLOGIN_R_SIZE_LIMIT) {

rb_str_resize(maybe_result, 0);

rb_syserr_fail(gle, "getlogin_r");

}

rb_str_modify_expand(maybe_result, loginsize);

login = RSTRING_PTR(maybe_result);

loginsize = rb_str_capacity(maybe_result);

}

if (login == NULL) {

rb_str_resize(maybe_result, 0);

return Qnil;

}

return maybe_result;

# elif USE_GETLOGIN

errno = 0;

login = getlogin();

if (errno) {

if (errno == ENOTTY || errno == ENXIO || errno == ENOENT) {

return Qnil;

}

rb_syserr_fail(errno, "getlogin");

}

return login ? rb_str_new_cstr(login) : Qnil;

# endif

#endif

}

VALUE

rb_getpwdirnam_for_login(VALUE login_name)

{

#if ( !defined(USE_GETPWNAM_R) && !defined(USE_GETPWNAM) )

return Qnil;

#else

if (NIL_P(login_name)) {

/* nothing to do; no name with which to query the password database */

return Qnil;

}

char *login = RSTRING_PTR(login_name);

struct passwd *pwptr;

# ifdef USE_GETPWNAM_R

struct passwd pwdnm;

char *bufnm;

long bufsizenm = GETPW_R_SIZE_INIT; /* maybe -1 */

if (bufsizenm < 0)

bufsizenm = GETPW_R_SIZE_DEFAULT;

VALUE getpwnm_tmp = rb_str_tmp_new(bufsizenm);

bufnm = RSTRING_PTR(getpwnm_tmp);

bufsizenm = rb_str_capacity(getpwnm_tmp);

rb_str_set_len(getpwnm_tmp, bufsizenm);

int enm;

errno = 0;

while ((enm = getpwnam_r(login, &pwdnm, bufnm, bufsizenm, &pwptr)) != 0) {

if (enm == ENOENT || enm== ESRCH || enm == EBADF || enm == EPERM) {

/* not found; non-errors */

rb_str_resize(getpwnm_tmp, 0);

return Qnil;

}

if (enm != ERANGE || bufsizenm >= GETPW_R_SIZE_LIMIT) {

rb_str_resize(getpwnm_tmp, 0);

rb_syserr_fail(enm, "getpwnam_r");

}

rb_str_modify_expand(getpwnm_tmp, bufsizenm);

bufnm = RSTRING_PTR(getpwnm_tmp);

bufsizenm = rb_str_capacity(getpwnm_tmp);

}

if (pwptr == NULL) {

/* no record in the password database for the login name */

rb_str_resize(getpwnm_tmp, 0);

return Qnil;

}

/* found it */

VALUE result = rb_str_new_cstr(pwptr->pw_dir);

rb_str_resize(getpwnm_tmp, 0);

return result;

# elif USE_GETPWNAM

errno = 0;

pwptr = getpwnam(login);

if (pwptr) {

/* found it */

return rb_str_new_cstr(pwptr->pw_dir);

}

if (errno

/* avoid treating as errors errno values that indicate "not found" */

&& ( errno != ENOENT && errno != ESRCH && errno != EBADF && errno != EPERM)) {

rb_syserr_fail(errno, "getpwnam");

}

return Qnil; /* not found */

# endif

#endif

}

/**

* Look up the user's dflt home dir in the password db, by uid.

*/

VALUE

rb_getpwdiruid(void)

{

# if !defined(USE_GETPWUID_R) && !defined(USE_GETPWUID)

/* Should never happen... </famous-last-words> */

return Qnil;

# else

uid_t ruid = getuid();

struct passwd *pwptr;

# ifdef USE_GETPWUID_R

struct passwd pwdid;

char *bufid;

long bufsizeid = GETPW_R_SIZE_INIT; /* maybe -1 */

if (bufsizeid < 0)

bufsizeid = GETPW_R_SIZE_DEFAULT;

VALUE getpwid_tmp = rb_str_tmp_new(bufsizeid);

bufid = RSTRING_PTR(getpwid_tmp);

bufsizeid = rb_str_capacity(getpwid_tmp);

rb_str_set_len(getpwid_tmp, bufsizeid);

int eid;

errno = 0;

while ((eid = getpwuid_r(ruid, &pwdid, bufid, bufsizeid, &pwptr)) != 0) {

if (eid == ENOENT || eid== ESRCH || eid == EBADF || eid == EPERM) {

/* not found; non-errors */

rb_str_resize(getpwid_tmp, 0);

return Qnil;

}

if (eid != ERANGE || bufsizeid >= GETPW_R_SIZE_LIMIT) {

rb_str_resize(getpwid_tmp, 0);

rb_syserr_fail(eid, "getpwuid_r");

}

rb_str_modify_expand(getpwid_tmp, bufsizeid);

bufid = RSTRING_PTR(getpwid_tmp);

bufsizeid = rb_str_capacity(getpwid_tmp);

}

if (pwptr == NULL) {

/* no record in the password database for the uid */

rb_str_resize(getpwid_tmp, 0);

return Qnil;

}

/* found it */

VALUE result = rb_str_new_cstr(pwptr->pw_dir);

rb_str_resize(getpwid_tmp, 0);

return result;

# elif defined(USE_GETPWUID)

errno = 0;

pwptr = getpwuid(ruid);

if (pwptr) {

/* found it */

return rb_str_new_cstr(pwptr->pw_dir);

}

if (errno

/* avoid treating as errors errno values that indicate "not found" */

&& ( errno == ENOENT || errno == ESRCH || errno == EBADF || errno == EPERM)) {

rb_syserr_fail(errno, "getpwuid");

}

return Qnil; /* not found */

# endif

#endif /* !defined(USE_GETPWUID_R) && !defined(USE_GETPWUID) */

}

#endif /* HAVE_PWD_H */