1 files changed, 47 insertions, 0 deletions
diff --git a/src/shutdown/hpr_wall.c b/src/shutdown/hpr_wall.c
new file mode 100644
index 0000000..cc6da5e
--- /dev/null
+++ b/src/shutdown/hpr_wall.c
@@ -0,0 +1,47 @@
+/* ISC license. */
+
+#include <string.h>
+#include <errno.h>
+#include <utmpx.h>
+
+#include <skalibs/posixishard.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/djbunix.h>
+
+#include "hpr.h"
+
+#ifndef UT_LINESIZE
+#define UT_LINESIZE 32
+#endif
+
+void hpr_wall (char const *s)
+{
+  size_t n = strlen(s) ;
+  char tty[10 + UT_LINESIZE] = "/dev/" ;
+  char msg[n+1] ;
+  memcpy(msg, s, n) ;
+  msg[n++] = '\n' ;
+  setutxent() ;
+  for (;;)
+  {
+    size_t linelen, idlen ;
+    struct utmpx *utx ;
+    int fd ;
+    errno = 0 ;
+    utx = getutxent() ;
+    if (!utx) break ;
+    if (utx->ut_type != USER_PROCESS) continue ;
+    linelen = strnlen(utx->ut_line, UT_LINESIZE) ;
+    idlen = strnlen(utx->ut_id, 4) ;
+    memcpy(tty + 5, utx->ut_line, linelen) ;
+    memcpy(tty + 5 + linelen, utx->ut_id, idlen) ;
+    tty[5 + linelen + idlen] = 0 ;
+    fd = open_append(tty) ;
+    if (fd == -1) continue ;
+    allwrite(fd, msg, n) ;
+    fd_close(fd) ;
+  }
+  if (errno) strerr_warnwu1sys("getutxent") ;
+  endutxent() ;
+}