output.c

linux下获取一些环境信息的代码

 *
 * So this isn't broken, but could be renamed to u98_std_stime,
 * as long as it still shows as STIME when using the -f option.
 */
static int pr_stime(char *restrict const outbuf, const proc_t *restrict const pp){
  struct tm *proc_time;
  struct tm *our_time;
  time_t t;
  const char *fmt;
  int tm_year;
  int tm_yday;
  our_time = localtime(&seconds_since_1970);   /* not reentrant */
  tm_year = our_time->tm_year;
  tm_yday = our_time->tm_yday;
  t = time_of_boot + pp->start_time / Hertz;
  proc_time = localtime(&t); /* not reentrant, this corrupts our_time */
  fmt = "%H:%M";                                   /* 03:02 23:59 */
  if(tm_yday != proc_time->tm_yday) fmt = "%b%d";  /* Jun06 Aug27 */
  if(tm_year != proc_time->tm_year) fmt = "%Y";    /* 1991 2001 */
  return strftime(outbuf, 42, fmt, proc_time);
}

static int pr_start(char *restrict const outbuf, const proc_t *restrict const pp){
  time_t t;
  char *str;
  t = time_of_boot + pp->start_time / Hertz;
  str = ctime(&t);
  if(str[8]==' ')  str[8]='0';
  if(str[11]==' ') str[11]='0';
  if((unsigned long)t+60*60*24 > seconds_since_1970)
    return snprintf(outbuf, COLWID, "%8.8s", str+11);
  return snprintf(outbuf, COLWID, "  %6.6s", str+4);
}


#ifdef SIGNAL_STRING
static int help_pr_sig(char *restrict const outbuf, const char *restrict const sig){
  long len = 0;
  len = strlen(sig);
  if(wide_signals){
    if(len>8) return snprintf(outbuf, COLWID, "%s", sig);
    return snprintf(outbuf, COLWID, "00000000%s", sig);
  }
  if(len-strspn(sig,"0") > 8)
    return snprintf(outbuf, COLWID, "<%s", sig+len-8);
  return snprintf(outbuf, COLWID,  "%s", sig+len-8);
}
#else
static int help_pr_sig(unsigned long long sig){
  if(wide_signals) return snprintf(outbuf, COLWID, "%016Lx", sig);
  if(sig>>32)      return snprintf(outbuf, COLWID, "<%08Lx", sig&0xffffffffLL);
  return                  snprintf(outbuf, COLWID,  "%08Lx", sig&0xffffffffLL);
}
#endif

static int pr_sig(char *restrict const outbuf, const proc_t *restrict const pp){
  return help_pr_sig(outbuf, pp->signal);
}
static int pr_sigmask(char *restrict const outbuf, const proc_t *restrict const pp){
  return help_pr_sig(outbuf, pp->blocked);
}
static int pr_sigignore(char *restrict const outbuf, const proc_t *restrict const pp){
  return help_pr_sig(outbuf, pp->sigignore);
}
static int pr_sigcatch(char *restrict const outbuf, const proc_t *restrict const pp){
  return help_pr_sig(outbuf, pp->sigcatch);
}


////////////////////////////////////////////////////////////////////////////////

/*
 * internal terms:  ruid  euid  suid  fuid
 * kernel vars:      uid  euid  suid fsuid
 * command args:    ruid   uid svuid   n/a
 */

static int pr_egid(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%d", pp->egid);
}
static int pr_rgid(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%d", pp->rgid);
}
static int pr_sgid(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%d", pp->sgid);
}
static int pr_fgid(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%d", pp->fgid);
}

static int pr_euid(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%d", pp->euid);
}
static int pr_ruid(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%d", pp->ruid);
}
static int pr_suid(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%d", pp->suid);
}
static int pr_fuid(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%d", pp->fuid);
}

// The Open Group Base Specifications Issue 6 (IEEE Std 1003.1, 2004 Edition)
// requires that user and group names print as decimal numbers if there is
// not enough room in the column, so tough luck if you don't like it.
//
// The UNIX and POSIX way to change column width is to rename it:
//      ps -o pid,user=CumbersomeUserNames -o comm
// The easy way is to directly specify the desired width:
//      ps -o pid,user:19,comm
//
static int do_pr_name(char *restrict const outbuf, const char *restrict const name, unsigned u){
  if(!user_is_number){
    int rightward = OUTBUF_SIZE;	/* max cells */
    int len;				/* real cells */
    
    escape_str(outbuf, name, OUTBUF_SIZE, &rightward);
    len = OUTBUF_SIZE-rightward;
    
    if(len <= (int)max_rightward)
      return len;  /* returns number of cells */
  }
  return snprintf(outbuf, COLWID, "%u", u);
}

static int pr_ruser(char *restrict const outbuf, const proc_t *restrict const pp){
  return do_pr_name(outbuf, pp->ruser, pp->ruid);
}
static int pr_euser(char *restrict const outbuf, const proc_t *restrict const pp){
  return do_pr_name(outbuf, pp->euser, pp->euid);
}
static int pr_fuser(char *restrict const outbuf, const proc_t *restrict const pp){
  return do_pr_name(outbuf, pp->fuser, pp->fuid);
}
static int pr_suser(char *restrict const outbuf, const proc_t *restrict const pp){
  return do_pr_name(outbuf, pp->suser, pp->suid);
}

static int pr_egroup(char *restrict const outbuf, const proc_t *restrict const pp){
  return do_pr_name(outbuf, pp->egroup, pp->egid);
}
static int pr_rgroup(char *restrict const outbuf, const proc_t *restrict const pp){
  return do_pr_name(outbuf, pp->rgroup, pp->rgid);
}
static int pr_fgroup(char *restrict const outbuf, const proc_t *restrict const pp){
  return do_pr_name(outbuf, pp->fgroup, pp->fgid);
}
static int pr_sgroup(char *restrict const outbuf, const proc_t *restrict const pp){
  return do_pr_name(outbuf, pp->sgroup, pp->sgid);
}

//////////////////////////////////////////////////////////////////////////////////

// TID tid LWP lwp SPID spid
static int pr_thread(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%u", pp->tid);
}
// thcount THCNT
static int pr_nlwp(char *restrict const outbuf, const proc_t *restrict const pp){
    return snprintf(outbuf, COLWID, "%d", pp->nlwp);
}

static int pr_sess(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%u", pp->session);
}
static int pr_tpgid(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%d", pp->tpgid);
}


/* SGI uses "cpu" to print the processor ID with header "P" */
static int pr_sgi_p(char *restrict const outbuf, const proc_t *restrict const pp){          /* FIXME */
  if(pp->state == 'R') return snprintf(outbuf, COLWID, "%d", pp->processor);
  return snprintf(outbuf, COLWID, "*");
}


/****************** FLASK & seLinux security stuff **********************/
// move the bulk of this to libproc sometime

static int pr_context(char *restrict const outbuf, const proc_t *restrict const pp){
  char filename[48];
  size_t len;
  ssize_t num_read;
  int fd;

// wchan file is suitable for testing
//snprintf(filename, sizeof filename, "/proc/%d/wchan", pp->tgid);
snprintf(filename, sizeof filename, "/proc/%d/attr/current", pp->tgid);

  fd = open(filename, O_RDONLY, 0);
  if(likely(fd==-1)) goto fail;
  num_read = read(fd, outbuf, 666);
  close(fd);
  if(unlikely(num_read<=0)) goto fail;
  outbuf[num_read] = '\0';

  len = 0;
  while(outbuf[len]>' ' && outbuf[len]<='~') len++;
  outbuf[len] = '\0';
  if(len) return len;

fail:
  outbuf[0] = '-';
  outbuf[1] = '\0';
  return 1;
}

#if 0
// This needs more study, considering:
// 1. the static linking option (maybe disable this in that case)
// 2. the -z and -Z option issue
// 3. width of output
static int pr_context(char *restrict const outbuf, const proc_t *restrict const pp){
  static int (*ps_getpidcon)(pid_t pid, char **context) = 0;
  static int tried_load = 0;
  size_t len;
  char *context;

  if(!ps_getpidcon && !tried_load){
    void *handle = dlopen("libselinux.so.1", RTLD_NOW);
    if(handle){
      dlerror();
      ps_getpidcon = dlsym(handle, "getpidcon");
      if(dlerror())
        ps_getpidcon = 0;
    }
    tried_load++;
  }
  if(ps_getpidcon && !ps_getpidcon(pp->tgid, &context)){
    size_t max_len = OUTBUF_SIZE-1;
    len = strlen(context);
    if(len > max_len) len = max_len;
    memcpy(outbuf, context, len);
    outbuf[len] = '\0';
    free(context);
  }else{
    outbuf[0] = '-';
    outbuf[1] = '\0';
    len = 1;
  }
  return len;
}
#endif


////////////////////////////// Test code /////////////////////////////////

// like "args"
static int pr_t_unlimited(char *restrict const outbuf, const proc_t *restrict const pp){
  static const char *const vals[] = {"[123456789-12345] <defunct>","ps","123456789-123456"};
  (void)pp;
  snprintf(outbuf, max_rightward+1, "%s", vals[lines_to_next_header%3u]);
  return strlen(outbuf);
}
static int pr_t_unlimited2(char *restrict const outbuf, const proc_t *restrict const pp){
  static const char *const vals[] = {"unlimited", "[123456789-12345] <defunct>","ps","123456789-123456"};
  (void)pp;
  snprintf(outbuf, max_rightward+1, "%s", vals[lines_to_next_header%4u]);
  return strlen(outbuf);
}

// like "etime"
static int pr_t_right(char *restrict const outbuf, const proc_t *restrict const pp){
  static const char *const vals[] = {"999-23:59:59","99-23:59:59","9-23:59:59","59:59"};
  (void)pp;
  return snprintf(outbuf, COLWID, "%s", vals[lines_to_next_header%4u]);
}
static int pr_t_right2(char *restrict const outbuf, const proc_t *restrict const pp){
  static const char *const vals[] = {"999-23:59:59","99-23:59:59","9-23:59:59"};
  (void)pp;
  return snprintf(outbuf, COLWID, "%s", vals[lines_to_next_header%3u]);
}

// like "tty"
static int pr_t_left(char *restrict const outbuf, const proc_t *restrict const pp){
  static const char *const vals[] = {"tty7","pts/9999","iseries/vtty42","ttySMX0","3270/tty4"};
  (void)pp;
  return snprintf(outbuf, COLWID, "%s", vals[lines_to_next_header%5u]);
}
static int pr_t_left2(char *restrict const outbuf, const proc_t *restrict const pp){
  static const char *const vals[] = {"tty7","pts/9999","ttySMX0","3270/tty4"};
  (void)pp;
  return snprintf(outbuf, COLWID, "%s", vals[lines_to_next_header%4u]);
}

/***************************************************************************/
/*************************** other stuff ***********************************/

/*
 * Old header specifications.
 *
 * short   Up  "  PID TTY STAT  TIME COMMAND"
 * long  l Pp  " FLAGS   UID   PID  PPID PRI  NI   SIZE   RSS WCHAN       STA TTY TIME COMMAND
 * user  u up  "USER       PID %CPU %MEM  SIZE   RSS TTY STAT START   TIME COMMAND
 * jobs  j gPp " PPID   PID  PGID   SID TTY TPGID  STAT   UID   TIME COMMAND
 * sig   s p   "  UID   PID SIGNAL   BLOCKED  IGNORED  CATCHED  STAT TTY   TIME COMMAND
 * vm    v r   "  PID TTY STAT  TIME  PAGEIN TSIZ DSIZ  RSS   LIM %MEM COMMAND
 * m     m r   "  PID TTY MAJFLT MINFLT   TRS   DRS  SIZE  SWAP   RSS  SHRD   LIB  DT COMMAND
 * regs  X p   "NR   PID    STACK      ESP      EIP TMOUT ALARM STAT TTY   TIME COMMAND
 */

/*
 * Unix98 requires that the heading for tty is TT, though XPG4, Digital,