skalibs

Mirror/fork of https://skarnet.org/software/skalibs/
git clone https://ccx.te2000.cz/git/skalibs
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sagethostname.c (635B)

      1 /* ISC license. */
      2 
      3 #include <unistd.h>
      4 #include <string.h>
      5 #include <errno.h>
      6 #include <skalibs/stralloc.h>
      7 #include <skalibs/djbunix.h>
      8 
      9 int sagethostname (stralloc *sa)
     10 {
     11   size_t n = 32 ;
     12   int e = errno ;
     13   int wasnull = !sa->s ;
     14 
     15   for (;;)
     16   {
     17     if (!stralloc_readyplus(sa, n)) goto err ;
     18     sa->s[sa->len + n - 2] = 0 ;
     19     errno = 0 ;
     20     if (gethostname(sa->s + sa->len, n) < 0)
     21     {
     22       if (errno != ENAMETOOLONG) goto err ;
     23     }
     24     else if (!sa->s[sa->len + n - 2]) break ;
     25     n += 32 ;
     26   }
     27   sa->len += strlen(sa->s + sa->len) ;
     28   errno = e ;
     29   return 0 ;
     30 
     31 err:
     32   if (wasnull) stralloc_free(sa) ;
     33   return -1 ;
     34 }