output.c

linux下获取一些环境信息的代码

    case '+': strcpy(q, "  "); break;
    case '|': strcpy(q, "  "); break;
    case '\0': return q-outbuf;    /* redundant & not used */
    }
    if (rightward-2 < 0) {
      *(q+rightward)='\0';
      return max_rightward;
    }
    q += 2;
    rightward -= 2;
    p++;
  }
  return q-outbuf;   /* gcc likes this here */
}


/* XPG4-UNIX, according to Digital:
The "args" and "command" specifiers show what was passed to the command.
Modifications to the arguments are not shown.
*/

/*
 * pp->cmd       short accounting name (comm & ucomm)
 * pp->cmdline   long name with args (args & command)
 * pp->environ   environment
 */

// FIXME: some of these may hit the guard page in forest mode

/* "command" is the same thing: long unless c */
static int pr_args(char *restrict const outbuf, const proc_t *restrict const pp){
  char *endp = outbuf;
  unsigned flags;
  int rightward=max_rightward;

  if(forest_prefix){
    int fh = forest_helper(outbuf);
    endp += fh;
    rightward -= fh;
  }
  if(bsd_c_option) flags = ESC_DEFUNCT;
  else             flags = ESC_DEFUNCT | ESC_BRACKETS | ESC_ARGS;
  endp += escape_command(endp, pp, OUTBUF_SIZE, &rightward, flags);

  if(bsd_e_option && rightward>1){
    const char **env = (const char**)pp->environ;
    if(env && *env){
      *endp++ = ' ';
      rightward--;
      endp += escape_strlist(endp, env, OUTBUF_SIZE, &rightward);
    }
  }
  //return endp - outbuf;
  return max_rightward-rightward;
}

/* "ucomm" is the same thing: short unless -f */
static int pr_comm(char *restrict const outbuf, const proc_t *restrict const pp){
  char *endp = outbuf;
  unsigned flags;
  int rightward=max_rightward;
  
  if(forest_prefix){
    int fh = forest_helper(outbuf);
    endp += fh;
    rightward -= fh;
  }
  if(unix_f_option) flags = ESC_DEFUNCT | ESC_BRACKETS | ESC_ARGS;
  else              flags = ESC_DEFUNCT;
  endp += escape_command(endp, pp, OUTBUF_SIZE, &rightward, flags);

  if(bsd_e_option && rightward>1){
    const char **env = (const char**)pp->environ;
    if(env && *env){
      *endp++ = ' ';
      rightward--;
      endp += escape_strlist(endp, env, OUTBUF_SIZE, &rightward);
    }
  }
  //return endp - outbuf;
  return max_rightward-rightward;
}
/* Non-standard, from SunOS 5 */
static int pr_fname(char *restrict const outbuf, const proc_t *restrict const pp){
  char *endp = outbuf;
  int rightward = max_rightward;
  
  if(forest_prefix){
    int fh = forest_helper(outbuf);
    endp += fh;
    rightward -= fh;
  }
  if (rightward>8)  /* 8=default, but forest maybe feeds more */
    rightward = 8;
  
  endp += escape_str(endp, pp->cmd, OUTBUF_SIZE, &rightward);
  //return endp - outbuf;
  return max_rightward-rightward;
}

/* elapsed wall clock time, [[dd-]hh:]mm:ss format (not same as "time") */
static int pr_etime(char *restrict const outbuf, const proc_t *restrict const pp){
  unsigned long t;
  unsigned dd,hh,mm,ss;
  char *cp = outbuf;
  t = seconds_since_boot - (unsigned long)(pp->start_time / Hertz);
  ss = t%60;
  t /= 60;
  mm = t%60;
  t /= 60;
  hh = t%24;
  t /= 24;
  dd = t;
  cp +=(     dd      ?  snprintf(cp, COLWID, "%u-", dd)           :  0 );
  cp +=( (dd || hh)  ?  snprintf(cp, COLWID, "%02u:", hh)         :  0 );
  cp +=                 snprintf(cp, COLWID, "%02u:%02u", mm, ss)       ;
  return (int)(cp-outbuf);
}

/* "Processor utilisation for scheduling."  --- we use %cpu w/o fraction */
static int pr_c(char *restrict const outbuf, const proc_t *restrict const pp){
  unsigned long long total_time;   /* jiffies used by this process */
  unsigned pcpu = 0;               /* scaled %cpu, 99 means 99% */
  unsigned long long seconds;      /* seconds of process life */
  total_time = pp->utime + pp->stime;
  if(include_dead_children) total_time += (pp->cutime + pp->cstime);
  seconds = seconds_since_boot - pp->start_time / Hertz;
  if(seconds) pcpu = (total_time * 100ULL / Hertz) / seconds;
  if (pcpu > 99U) pcpu = 99U;
  return snprintf(outbuf, COLWID, "%2u", pcpu);
}
/* normal %CPU in ##.# format. */
static int pr_pcpu(char *restrict const outbuf, const proc_t *restrict const pp){
  unsigned long long total_time;   /* jiffies used by this process */
  unsigned pcpu = 0;               /* scaled %cpu, 999 means 99.9% */
  unsigned long long seconds;      /* seconds of process life */
  total_time = pp->utime + pp->stime;
  if(include_dead_children) total_time += (pp->cutime + pp->cstime);
  seconds = seconds_since_boot - pp->start_time / Hertz;
  if(seconds) pcpu = (total_time * 1000ULL / Hertz) / seconds;
  if (pcpu > 999U)
    return snprintf(outbuf, COLWID, "%u", pcpu/10U);
  return snprintf(outbuf, COLWID, "%u.%u", pcpu/10U, pcpu%10U);
}
/* this is a "per-mill" format, like %cpu with no decimal point */
static int pr_cp(char *restrict const outbuf, const proc_t *restrict const pp){
  unsigned long long total_time;   /* jiffies used by this process */
  unsigned pcpu = 0;               /* scaled %cpu, 999 means 99.9% */
  unsigned long long seconds;      /* seconds of process life */
  total_time = pp->utime + pp->stime;
  if(include_dead_children) total_time += (pp->cutime + pp->cstime);
  seconds = seconds_since_boot - pp->start_time / Hertz ;
  if(seconds) pcpu = (total_time * 1000ULL / Hertz) / seconds;
  if (pcpu > 999U) pcpu = 999U;
  return snprintf(outbuf, COLWID, "%3u", pcpu);
}

static int pr_pgid(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%u", pp->pgrp);
}
static int pr_pid(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%u", pp->tgid);
}
static int pr_ppid(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%u", pp->ppid);
}


/* cumulative CPU time, [dd-]hh:mm:ss format (not same as "etime") */
static int pr_time(char *restrict const outbuf, const proc_t *restrict const pp){
  unsigned long t;
  unsigned dd,hh,mm,ss;
  int c;
  t = (pp->utime + pp->stime) / Hertz;
  ss = t%60;
  t /= 60;
  mm = t%60;
  t /= 60;
  hh = t%24;
  t /= 24;
  dd = t;
  c  =( dd ? snprintf(outbuf, COLWID, "%u-", dd) : 0              );
  c +=( snprintf(outbuf+c, COLWID, "%02u:%02u:%02u", hh, mm, ss)    );
  return c;
}

/* HP-UX puts this (I forget, vsz or vsize?) in kB and uses "sz" for pages.
 * Unix98 requires "vsz" to be kB.
 * Tru64 does both vsize and vsz like "1.23M"
 *
 * Our pp->vm_size is kB and our pp->vsize is pages.
 *
 * TODO: add flag for "1.23M" behavior, on this and other columns.
 */
static int pr_vsz(char *restrict const outbuf, const proc_t *restrict const pp){
  return snprintf(outbuf, COLWID, "%lu", pp->vm_size);
}

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

// "PRI" is created by "opri", or by "pri" when -c is used.
//
// Unix98 only specifies that a high "PRI" is low priority.
// Sun and SCO add the -c behavior. Sun defines "pri" and "opri".
// Linux may use "priority" for historical purposes.
//
// According to the kernel's fs/proc/array.c and kernel/sched.c source,
// the kernel reports it in /proc via this:
//        p->prio - MAX_RT_PRIO
// such that "RT tasks are offset by -200. Normal tasks are centered
// around 0, value goes from -16 to +15" but who knows if that is
// before or after the conversion...
//
// <linux/sched.h> says:
// MAX_RT_PRIO is currently 100.       (so we see 0 in /proc)
// RT tasks have a p->prio of 0 to 99. (so we see -100 to -1)
// non-RT tasks are from 100 to 139.   (so we see 0 to 39)
// Lower values have higher priority, as in the UNIX standard.
//
// In any case, pp->priority+100 should get us back to what the kernel
// has for p->prio.
//
// Test results with the "yes" program on a 2.6.x kernel:
//
// # ps -C19,_20 -o pri,opri,intpri,priority,ni,pcpu,pid,comm
// PRI PRI PRI PRI  NI %CPU  PID COMMAND
//   0  99  99  39  19 10.6 8686 19
//  34  65  65   5 -20 94.7 8687 _20
//
// Grrr. So the UNIX standard "PRI" must NOT be from "pri".
// Either of the others will do. We use "opri" for this.
// (and use "pri" when the "-c" option is used)
// Probably we should have Linux-specific "pri_for_l" and "pri_for_lc"
//
// sched_get_priority_min.2 says the Linux static priority is
// 1..99 for RT and 0 for other... maybe 100 is kernel-only?
//
// A nice range would be -99..0 for RT and 1..40 for normal,
// which is pp->priority+1. (3-digit max, positive is normal,
// negative or 0 is RT, and meets the standard for PRI)
//

// legal as UNIX "PRI"
// "priority"         (was -20..20, now -100..39)
static int pr_priority(char *restrict const outbuf, const proc_t *restrict const pp){    /* -20..20 */
    return snprintf(outbuf, COLWID, "%ld", pp->priority);
}

// legal as UNIX "PRI"
// "intpri" and "opri" (was 39..79, now  -40..99)
static int pr_opri(char *restrict const outbuf, const proc_t *restrict const pp){        /* 39..79 */
    return snprintf(outbuf, COLWID, "%ld", 60 + pp->priority);
}

// legal as UNIX "PRI"
// "pri_foo"   --  match up w/ nice values of sleeping processes (-120..19)
static int pr_pri_foo(char *restrict const outbuf, const proc_t *restrict const pp){
    return snprintf(outbuf, COLWID, "%ld", pp->priority - 20);
}

// legal as UNIX "PRI"
// "pri_bar"   --  makes RT pri show as negative       (-99..40)
static int pr_pri_bar(char *restrict const outbuf, const proc_t *restrict const pp){
    return snprintf(outbuf, COLWID, "%ld", pp->priority + 1);
}

// legal as UNIX "PRI"
// "pri_baz"   --  the kernel's ->prio value, as of Linux 2.6.8     (1..140)
static int pr_pri_baz(char *restrict const outbuf, const proc_t *restrict const pp){
    return snprintf(outbuf, COLWID, "%ld", pp->priority + 100);
}


// not legal as UNIX "PRI"
// "pri"               (was 20..60, now    0..139)
static int pr_pri(char *restrict const outbuf, const proc_t *restrict const pp){         /* 20..60 */
    return snprintf(outbuf, COLWID, "%ld", 39 - pp->priority);
}

// not legal as UNIX "PRI"
// "pri_api"   --  match up w/ RT API    (-40..99)
static int pr_pri_api(char *restrict const outbuf, const proc_t *restrict const pp){
    return snprintf(outbuf, COLWID, "%ld", -1 - pp->priority);
}

static int pr_nice(char *restrict const outbuf, const proc_t *restrict const pp){
  if(pp->sched!=0 && pp->sched!=-1) return snprintf(outbuf, COLWID, "-");
  return snprintf(outbuf, COLWID, "%ld", pp->nice);
}

// HP-UX   "cls": RT RR RR2 ???? HPUX FIFO KERN
// Solaris "class": SYS TS FX IA RT FSS (FIFO is RR w/ Inf quant)
//                  FIFO+RR share RT; FIFO has Inf quant
//                  IA=interactive; FX=fixed; TS=timeshare; SYS=system
//                  FSS=fairshare; INTS=interrupts
// Tru64   "policy": FF RR TS
// IRIX    "class": RT TS B BC WL GN
//                  RT=real-time; TS=time-share; B=batch; BC=batch-critical
//                  WL=weightless; GN=gang-scheduled
//                  see miser(1) for this; PRI has some letter codes too
static int pr_class(char *restrict const outbuf, const proc_t *restrict const pp){
  switch(pp->sched){
  case -1: return snprintf(outbuf, COLWID, "-");   // not reported
  case  0: return snprintf(outbuf, COLWID, "TS");  // SCHED_OTHER
  case  1: return snprintf(outbuf, COLWID, "FF");  // SCHED_FIFO