top.c

linux下获取一些环境信息的代码

/* top.c - Source file:         show Linux processes */
/*
 * Copyright (c) 2002, by:      James C. Warner
 *    All rights reserved.      8921 Hilloway Road
 *                              Eden Prairie, Minnesota 55347 USA
 *                             <[e-mail]>
 *
 * This file may be used subject to the terms and conditions of the
 * GNU Library General Public License Version 2, or any later version
 * at your option, as published by the Free Software Foundation.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 * 
 * For their contributions to this program, the author wishes to thank:
 *    Albert D. Cahalan, <[e-mail]>
 *    Craig Small, <[e-mail]>
 *
 * Changes by Albert Cahalan, 2002-2004.
 */
#include <sys/ioctl.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <ctype.h>
#include <curses.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// Foul POS defines all sorts of stuff...
#include <term.h>
#undef tab

#include <termios.h>
#include <time.h>
#include <unistd.h>
#include <values.h>

#include "proc/devname.h"
#include "proc/wchan.h"
#include "proc/procps.h"
#include "proc/readproc.h"
#include "proc/escape.h"
#include "proc/sig.h"
#include "proc/sysinfo.h"
#include "proc/version.h"
#include "proc/whattime.h"

#include "top.h"

/*######  Miscellaneous global stuff  ####################################*/

        /* The original and new terminal attributes */
static struct termios Savedtty,
                      Rawtty;
static int Ttychanged = 0;

        /* Program name used in error messages and local 'rc' file name */
static char *Myname;

        /* Name of user config file (dynamically constructed) and our
           'Current' rcfile contents, initialized with defaults but may be
           overridden with the local rcfile (old or new-style) values */
static char  Rc_name [OURPATHSZ];
static RCF_t Rc = DEF_RCFILE;

        /* The run-time acquired page size */
static unsigned Page_size;
static unsigned page_to_kb_shift;

        /* SMP Irix/Solaris mode */
static int  Cpu_tot;
static double pcpu_max_value;  // usually 99.9, for %CPU display
        /* assume no IO-wait stats, overridden if linux 2.5.41 */
static const char *States_fmts = STATES_line2x4;

        /* Specific process id monitoring support */
static pid_t Monpids [MONPIDMAX] = { 0 };
static int   Monpidsidx = 0;

        /* A postponed error message */
static char Msg_delayed [SMLBUFSIZ];
static int  Msg_awaiting = 0;

// This is the select() timeout. Clear it in sig handlers to avoid a race.
// (signal happens just as we are about to select() and thus does not
// break us out of the select(), causing us to delay until timeout)
static volatile struct timeval tv;
#define ZAP_TIMEOUT do{tv.tv_usec=0; tv.tv_sec=0;}while(0);

        /* Configurable Display support ##################################*/

        /* Current screen dimensions.
           note: the number of processes displayed is tracked on a per window
                 basis (see the WIN_t).  Max_lines is the total number of
                 screen rows after deducting summary information overhead. */
        /* Current terminal screen size. */
static int Screen_cols, Screen_rows, Max_lines;

// set to 1 if writing to the last column would be troublesome
// (we don't distinguish the lowermost row from the other rows)
static int avoid_last_column;

        /* This is really the number of lines needed to display the summary
           information (0 - nn), but is used as the relative row where we
           stick the cursor between frames. */
static int Msg_row;

        /* Global/Non-windows mode stuff that is NOT persistent */
static int No_ksyms = -1,       // set to '0' if ksym avail, '1' otherwise
           PSDBopen = 0,        // set to '1' if psdb opened (now postponed)
           Batch = 0,           // batch mode, collect no input, dumb output
           Loops = -1,          // number of iterations, -1 loops forever
           Secure_mode = 0;     // set if some functionality restricted

        /* Some cap's stuff to reduce runtime calls --
           to accomodate 'Batch' mode, they begin life as empty strings */
static char  Cap_clr_eol    [CAPBUFSIZ],
             Cap_clr_eos    [CAPBUFSIZ],
             Cap_clr_scr    [CAPBUFSIZ],
             Cap_rmam       [CAPBUFSIZ],
             Cap_smam       [CAPBUFSIZ],
             Cap_curs_norm  [CAPBUFSIZ],
             Cap_curs_huge  [CAPBUFSIZ],
             Cap_home       [CAPBUFSIZ],
             Cap_norm       [CAPBUFSIZ],
             Cap_reverse    [CAPBUFSIZ],
             Caps_off       [CAPBUFSIZ];
static int   Cap_can_goto = 0;

        /* Some optimization stuff, to reduce output demands...
           The Pseudo_ guys are managed by wins_resize and frame_make.  They
           are exploited in a macro and represent 90% of our optimization.
           The Stdout_buf is transparent to our code and regardless of whose
           buffer is used, stdout is flushed at frame end or if interactive. */
static char *Pseudo_scrn;
static int   Pseudo_row, Pseudo_cols, Pseudo_size;
#ifndef STDOUT_IOLBF
        // less than stdout's normal buffer but with luck mostly '\n' anyway
static char  Stdout_buf[2048];
#endif


        /* ////////////////////////////////////////////////////////////// */
        /* Special Section: multiple windows/field groups  ---------------*/

        /* The pointers to our four WIN_t's, and which of those is considered
           the 'current' window (ie. which window is associated with any summ
           info displayed and to which window commands are directed) */
static WIN_t Winstk [GROUPSMAX],
             *Curwin;

        /* Frame oriented stuff that can't remain local to any 1 function
           and/or that would be too cumbersome managed as parms,
           and/or that are simply more efficiently handled as globals
           (first 2 persist beyond a single frame, changed infrequently) */
static int       Frames_libflags;       // PROC_FILLxxx flags (0 = need new)
//atic int       Frames_maxcmdln;       // the largest from the 4 windows
static unsigned  Frame_maxtask;         // last known number of active tasks
                                        // ie. current 'size' of proc table
static unsigned  Frame_running,         // state categories for this frame
                 Frame_sleepin,
                 Frame_stopped,
                 Frame_zombied;
static float     Frame_tscale;          // so we can '*' vs. '/' WHEN 'pcpu'
static int       Frame_srtflg,          // the subject window's sort direction
                 Frame_ctimes,          // the subject window's ctimes flag
                 Frame_cmdlin;          // the subject window's cmdlin flag
        /* ////////////////////////////////////////////////////////////// */


/*######  Sort callbacks  ################################################*/

        /*
         * These happen to be coded in the same order as the enum 'pflag'
         * values.  Note that 2 of these routines serve double duty --
         * 2 columns each.
         */

SCB_NUMx(P_PID, XXXID)
SCB_NUMx(P_PPD, ppid)
SCB_STRx(P_URR, ruser)
SCB_NUMx(P_UID, euid)
SCB_STRx(P_URE, euser)
SCB_STRx(P_GRP, egroup)
SCB_NUMx(P_TTY, tty)
SCB_NUMx(P_PRI, priority)
SCB_NUMx(P_NCE, nice)
SCB_NUMx(P_CPN, processor)
SCB_NUM1(P_CPU, pcpu)
                                        // also serves P_TM2 !
static int sort_P_TME (const proc_t **P, const proc_t **Q)
{
   if (Frame_ctimes) {
      if ( ((*P)->cutime + (*P)->cstime + (*P)->utime + (*P)->stime)
        < ((*Q)->cutime + (*Q)->cstime + (*Q)->utime + (*Q)->stime) )
           return SORT_lt;
      if ( ((*P)->cutime + (*P)->cstime + (*P)->utime + (*P)->stime)
        > ((*Q)->cutime + (*Q)->cstime + (*Q)->utime + (*Q)->stime) )
           return SORT_gt;
   } else {
      if ( ((*P)->utime + (*P)->stime) < ((*Q)->utime + (*Q)->stime))
         return SORT_lt;
      if ( ((*P)->utime + (*P)->stime) > ((*Q)->utime + (*Q)->stime))
         return SORT_gt;
   }
   return SORT_eq;
}

SCB_NUM1(P_VRT, size)
SCB_NUM2(P_SWP, size, resident)
SCB_NUM1(P_RES, resident)               // also serves P_MEM !
SCB_NUM1(P_COD, trs)
SCB_NUM1(P_DAT, drs)
SCB_NUM1(P_SHR, share)
SCB_NUM1(P_FLT, maj_flt)
SCB_NUM1(P_DRT, dt)
SCB_NUMx(P_STA, state)

static int sort_P_CMD (const proc_t **P, const proc_t **Q)
{
   /* if a process doesn't have a cmdline, we'll consider it a kernel thread
      -- since displayed tasks are given special treatment, we must too */
   if (Frame_cmdlin && ((*P)->cmdline || (*Q)->cmdline)) {
      if (!(*Q)->cmdline) return Frame_srtflg * -1;
      if (!(*P)->cmdline) return Frame_srtflg;
      return Frame_srtflg *
         strncmp((*Q)->cmdline[0], (*P)->cmdline[0], (unsigned)Curwin->maxcmdln);
   }
   // this part also handles the compare if both are kernel threads
   return Frame_srtflg * strcmp((*Q)->cmd, (*P)->cmd);
}

SCB_NUM1(P_WCH, wchan)
SCB_NUM1(P_FLG, flags)

        /* ///////////////////////////////// special sort for prochlp() ! */
static int sort_HST_t (const HST_t *P, const HST_t *Q)
{
   return P->pid - Q->pid;
}


/*######  Tiny useful routine(s)  ########################################*/

        /*
         * This routine isolates ALL user INPUT and ensures that we
         * wont be mixing I/O from stdio and low-level read() requests */
static int chin (int ech, char *buf, unsigned cnt)
{
   int rc;

   fflush(stdout);
   if (!ech)
      rc = read(STDIN_FILENO, buf, cnt);
   else {
      tcsetattr(STDIN_FILENO, TCSAFLUSH, &Savedtty);
      rc = read(STDIN_FILENO, buf, cnt);
      tcsetattr(STDIN_FILENO, TCSAFLUSH, &Rawtty);
   }
   // may be the beginning of a lengthy escape sequence
   tcflush(STDIN_FILENO, TCIFLUSH);
   return rc;                   // note: we do NOT produce a vaid 'string'
}


// This routine simply formats whatever the caller wants and
// returns a pointer to the resulting 'const char' string...
static const char *fmtmk (const char *fmts, ...) __attribute__((format(printf,1,2)));
static const char *fmtmk (const char *fmts, ...)
{
   static char buf[BIGBUFSIZ];          // with help stuff, our buffer
   va_list va;                          // requirements exceed 1k

   va_start(va, fmts);
   vsnprintf(buf, sizeof(buf), fmts, va);
   va_end(va);
   return (const char *)buf;
}


// This guy is just our way of avoiding the overhead of the standard
// strcat function (should the caller choose to participate)
static inline char *scat (char *restrict dst, const char *restrict src)
{
   while (*dst) dst++;
   while ((*(dst++) = *(src++)));
   return --dst;
}


// Trim the rc file lines and any 'open_psdb_message' result which arrives
// with an inappropriate newline (thanks to 'sysmap_mmap')
static char *strim_0 (char *str)
{
   static const char ws[] = "\b\e\f\n\r\t\v\x9b";  // 0x9b is an escape
   char *p;

   if ((p = strpbrk(str, ws))) *p = 0;
   return str;
}


// This guy just facilitates Batch and protects against dumb ttys
// -- we'd 'inline' him but he's only called twice per frame,
// yet used in many other locations.
static const char *tg2 (int x, int y)
{
   return Cap_can_goto ? tgoto(cursor_address, x, y) : "";
}


/*######  Exit/Interrput routines  #######################################*/

// The usual program end -- called only by functions in this section.
static void bye_bye (FILE *fp, int eno, const char *str) NORETURN;
static void bye_bye (FILE *fp, int eno, const char *str)
{
   if (!Batch)
      tcsetattr(STDIN_FILENO, TCSAFLUSH, &Savedtty);
   putp(tg2(0, Screen_rows));
   putp(Cap_curs_norm);
   putp(Cap_smam);
   putp("\n");
   fflush(stdout);

//#define ATEOJ_REPORT
#ifdef ATEOJ_REPORT

   fprintf(fp,
      "\n\tTerminal: %s"
      "\n\t   device = %s, ncurses = v%s"
      "\n\t   max_colors = %d, max_pairs = %d"
      "\n\t   Cap_can_goto = %s"
      "\n\t   Screen_cols = %d, Screen_rows = %d"
      "\n\t   Max_lines = %d, most recent Pseudo_size = %d"
      "\n"
#ifdef PRETENDNOCAP
      , "dumb"
#else
      , termname()
#endif
      , ttyname(STDOUT_FILENO), NCURSES_VERSION
      , max_colors, max_pairs
      , Cap_can_goto ? "yes" : "No!"
      , Screen_cols, Screen_rows
      , Max_lines, Pseudo_size
      );

   fprintf(fp,
#ifndef STDOUT_IOLBF
      "\n\t   Stdout_buf = %d, BUFSIZ = %u"
#endif
      "\n\tWindows and Curwin->"
      "\n\t   sizeof(WIN_t) = %u, GROUPSMAX = %d"
      "\n\t   rc.winname = %s, grpname = %s"
      "\n\t   rc.winflags = %08x, maxpflgs = %d"
      "\n\t   rc.fieldscur = %s"
      "\n\t   winlines  = %d, rc.maxtasks = %d, maxcmdln = %d"
      "\n\t   rc.sortindx  = %d"
      "\n"
#ifndef STDOUT_IOLBF
      , sizeof(Stdout_buf), (unsigned)BUFSIZ
#endif
      , sizeof(WIN_t), GROUPSMAX
      , Curwin->rc.winname, Curwin->grpname
      , Curwin->rc.winflags, Curwin->maxpflgs
      , Curwin->rc.fieldscur
      , Curwin->winlines, Curwin->rc.maxtasks, Curwin->maxcmdln
      , Curwin->rc.sortindx
      );