#include <sys/types.h>#include <time.h>#include "datetime.h"#include "fork.h"#include "wait.h"#include "fd.h"#include "fmt.h"#include "strerr.h"#include "substdio.h"#include "subfd.h"#include "readwrite.h"#include "exit.h"#define FATAL "predate: fatal: "static char *montab[12] = {"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"};char num[FMT_ULONG];char outbuf[1024];void main(argc,argv)int argc;char **argv;{  time_t now;  struct tm *tm;  struct datetime dt;  datetime_sec utc;  datetime_sec local;  int minutes;  int pi[2];  substdio ss;  int wstat;  int pid;  sig_pipeignore();  if (!argv[1])    strerr_die1x(100,"predate: usage: predate child");  if (pipe(pi) == -1)    strerr_die2sys(111,FATAL,"unable to create pipe: ");  switch(pid = fork()) {    case -1:      strerr_die2sys(111,FATAL,"unable to fork: ");    case 0:      close(pi[1]);      if (fd_move(0,pi[0]) == -1)	strerr_die2sys(111,FATAL,"unable to set up fds: ");      sig_pipedefault();      execvp(argv[1],argv + 1);      strerr_die4sys(111,FATAL,"unable to run ",argv[1],": ");  }  close(pi[0]);  substdio_fdbuf(&ss,write,pi[1],outbuf,sizeof(outbuf));  time(&now);  tm = gmtime(&now);  dt.year = tm->tm_year;  dt.mon = tm->tm_mon;  dt.mday = tm->tm_mday;  dt.hour = tm->tm_hour;  dt.min = tm->tm_min;  dt.sec = tm->tm_sec;  utc = datetime_untai(&dt); /* utc == now, if gmtime ignores leap seconds */  tm = localtime(&now);  dt.year = tm->tm_year;  dt.mon = tm->tm_mon;  dt.mday = tm->tm_mday;  dt.hour = tm->tm_hour;  dt.min = tm->tm_min;  dt.sec = tm->tm_sec;  local = datetime_untai(&dt);  substdio_puts(&ss,"Date: ");  substdio_put(&ss,num,fmt_uint(num,dt.mday));  substdio_puts(&ss," ");  substdio_puts(&ss,montab[dt.mon]);  substdio_puts(&ss," ");  substdio_put(&ss,num,fmt_uint(num,dt.year + 1900));  substdio_puts(&ss," ");  substdio_put(&ss,num,fmt_uint0(num,dt.hour,2));  substdio_puts(&ss,":");  substdio_put(&ss,num,fmt_uint0(num,dt.min,2));  substdio_puts(&ss,":");  substdio_put(&ss,num,fmt_uint0(num,dt.sec,2));  if (local < utc) {    minutes = (utc - local + 30) / 60;    substdio_puts(&ss," -");    substdio_put(&ss,num,fmt_uint0(num,minutes / 60,2));    substdio_put(&ss,num,fmt_uint0(num,minutes % 60,2));  }  else {    minutes = (local - utc + 30) / 60;    substdio_puts(&ss," +");    substdio_put(&ss,num,fmt_uint0(num,minutes / 60,2));    substdio_put(&ss,num,fmt_uint0(num,minutes % 60,2));  }  substdio_puts(&ss,"\n");  substdio_copy(&ss,subfdin);  substdio_flush(&ss);  close(pi[1]);  if (wait_pid(&wstat,pid) == -1)    strerr_die2sys(111,FATAL,"wait failed: ");  if (wait_crashed(wstat))    strerr_die2x(111,FATAL,"child crashed");  _exit(wait_exitcode(wstat));}