preline.c

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#include <unistd.h>
#include "fd.h"
#include "buffer.h"
#include "exit.h"
#include "wait.h"
#include "env.h"
#include "sig.h"
#include "getoptb.h"
#include "logmsg.h"
 
#define WHO "preline"
 
void die_usage()
{
  logmsg(WHO,100,USAGE,"preline cmd [ arg ... ]");
}
 
int flagufline = 1; char *ufline;
int flagrpline = 1; char *rpline;
int flagdtline = 1; char *dtline;
 
char outbuf[BUFFER_OUTSIZE];
buffer bo = BUFFER_INIT(write,1,outbuf,sizeof(outbuf));
char inbuf[BUFFER_INSIZE];
buffer bi = BUFFER_INIT(read,0,inbuf,sizeof(inbuf));
 
int main(int argc, char **argv)
{
  int opt;
  int pi[2];
  int pid;
  int wstat;
 
  sig_pipeignore();
 
  if (!(ufline = env_get("UFLINE"))) die_usage();
  if (!(rpline = env_get("RPLINE"))) die_usage();
  if (!(dtline = env_get("DTLINE"))) die_usage();
 
  while ((opt = getopt(argc,argv,"frdFRD")) != opteof)
    switch (opt) {
      case 'f': flagufline = 0; break;
      case 'r': flagrpline = 0; break;
      case 'd': flagdtline = 0; break;
      case 'F': flagufline = 1; break;
      case 'R': flagrpline = 1; break;
      case 'D': flagdtline = 1; break;
      default: die_usage();
    }
  argc -= optind;
  argv += optind;
  if (!*argv) die_usage();
 
  if (pipe(pi) == -1)
    logmsg(WHO,111,FATAL,"unable to create pipe");
 
  pid = fork();
  if (pid == -1)
    logmsg(WHO,111,FATAL,"unable to fork");
 
  if (pid == 0) {
    close(pi[1]);
    if (fd_move(0,pi[0]) == -1)
      logmsg(WHO,111,FATAL,"unable to set up fds");
    sig_pipedefault();
    execvp(*argv,argv);
    logmsg(WHO,errno,FATAL,B("unable to run: ",*argv));
  }
  close(pi[0]);
  if (fd_move(1,pi[1]) == -1)
    logmsg(WHO,111,FATAL,"unable to set up fds");
 
  if (flagufline) buffer_puts(&bo,ufline);
  if (flagrpline) buffer_puts(&bo,rpline);
  if (flagdtline) buffer_puts(&bo,dtline);
  if (buffer_copy(&bo,&bi) != 0)
    logmsg(WHO,111,FATAL,"unable to copy input");
  buffer_flush(&bo);
  close(1);
 
  if (wait_pid(&wstat,pid) == -1)
    logmsg(WHO,111,FATAL,"wait failed");
  if (wait_crashed(wstat))
    logmsg(WHO,111,FATAL,"child crashed");
  _exit(wait_exitcode(wstat));
}