path: root/toys/posix/ps.c

/* ps.c - show process list
 *
 * Copyright 2015 Rob Landley <rob@landley.net>
 *
 * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ps.html
 * And http://kernel.org/doc/Documentation/filesystems/proc.txt Table 1-4
 * And linux kernel source fs/proc/array.c function do_task_stat()
 *
 * Deviations from posix: no -n because /proc/self/wchan exists; we use -n to
 * mean "show numeric users and groups" instead.
 * Posix says default output should have field named "TTY" but if you "-o tty"
 * the same field should be called "TT" which is _INSANE_ and I'm not doing it.
 * Similarly -f outputs USER but calls it UID (we call it USER).
 * It also says that -o "args" and "comm" should behave differently but use
 * the same title, which is not the same title as the default output. (No.)
 * Select by session id is -s not -g.
 *
 * Posix defines -o ADDR as "The address of the process" but the process
 * start address is a constant on any elf system with mmu. The procps ADDR
 * field always prints "-" with an alignment of 1, which is why it has 11
 * characters left for "cmd" in in 80 column "ps -l" mode. On x86-64 you
 * need 12 chars, leaving nothing for cmd: I.E. posix 2008 ps -l mode can't
 * be sanely implemented on 64 bit Linux systems. In procps there's ps -y
 * which changes -l by removing the "F" column and swapping RSS for ADDR,
 * leaving 9 chars for cmd, so we're using that as our -l output.
 *
 * Added a bunch of new -o fields posix doesn't mention, and we don't
 * label "ps -o command,args,comm" as "COMMAND COMMAND COMMAND". We don't
 * output argv[0] unmodified for -o comm or -o args (but procps violates
 * posix for -o comm anyway, it's stat[2] not argv[0]).
 *
 * TODO: ps aux (att & bsd style "ps -ax" vs "ps ax" behavior difference)
 * TODO: switch -fl to -y
 * TODO: thread support /proc/$d/task/%d/stat (and -o stat has "l")
 * TODO: iotop: Window size change: respond immediately. Why not padding
 *       at right edge? (Not adjusting to screen size at all? Header wraps?)

USE_PS(NEWTOY(ps, "k(sort)*P(ppid)*aAdeflno*p(pid)*s*t*u*U*g*G*wZ[!ol][+Ae]", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_LOCALE))
// stayroot because iotop needs root to read other process' proc/$$/io
USE_TOP(NEWTOY(top, ">0m" "p*u*d#=3<1n#<1bq", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_STAYROOT|TOYFLAG_LOCALE))
USE_IOTOP(NEWTOY(iotop, ">0Aako"  "p*u*d#=3<1n#<1bq", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_STAYROOT|TOYFLAG_LOCALE))
USE_PGREP(NEWTOY(pgrep, "?cld:u*U*t*s*P*g*G*fnovxL:", TOYFLAG_USR|TOYFLAG_BIN))
USE_PKILL(NEWTOY(pkill,     "Vu*U*t*s*P*g*G*fnovxl:", TOYFLAG_USR|TOYFLAG_BIN))

config PS
  bool "ps"
  default y
  help
    usage: ps [-AadeflnwZ] [-gG GROUP,] [-k FIELD,] [-o FIELD,] [-p PID,] [-t TTY,] [-uU USER,]

    List processes.

    Which processes to show (selections may be comma separated lists):

    -A	All processes
    -a	Processes with terminals that aren't session leaders
    -d	All processes that aren't session leaders
    -e	Same as -A
    -g	Belonging to GROUPs
    -G	Belonging to real GROUPs (before sgid)
    -p	PIDs (--pid)
    -P	Parent PIDs (--ppid)
    -s	In session IDs
    -t	Attached to selected TTYs
    -u	Owned by USERs
    -U	Owned by real USERs (before suid)

    Output modifiers:

    -k	Sort FIELDs in +increasing or -decreasting order (--sort)
    -n	Show numeric USER and GROUP
    -w	Wide output (don't truncate at terminal width)

    Which FIELDs to show. (Default = -o PID,TTY,TIME,CMD)

    -f	Full listing (-o USER:8=UID,PID,PPID,C,STIME,TTY,TIME,CMD)
    -l	Long listing (-o F,S,UID,PID,PPID,C,PRI,NI,ADDR,SZ,WCHAN,TTY,TIME,CMD)
    -o	Output the listed FIELDs, each with optional :size and/or =title
    -Z	Include LABEL

    Available -o FIELDs:

      ADDR  Instruction pointer               ARGS    Command line (argv[] -path)
      CMD   COMM without -f, ARGS with -f     CMDLINE Command line (argv[])
      COMM  Original command name             COMMAND Original command path
      CPU   Which processor running on        ETIME   Elapsed time since PID start
      F     Flags (1=FORKNOEXEC 4=SUPERPRIV)  GID     Group id
      GROUP Group name                        LABEL   Security label
      MAJFL Major page faults                 MINFL   Minor page faults
      NAME  Command name (argv[0])            NI      Niceness (lower is faster)
      PCPU  Percentage of CPU time used       PGID    Process Group ID
      PID   Process ID                        PPID    Parent Process ID
      PRI   Priority (higher is faster)       PSR     Processor last executed on
      RGID  Real (before sgid) group ID       RGROUP  Real (before sgid) group name
      RSS   Resident Set Size (pages in use)  RTPRIO  Realtime priority
      RUID  Real (before suid) user ID        RUSER   Real (before suid) user name
      S     Process state:
            R (running) S (sleeping) D (device I/O) T (stopped)  t (traced)
            Z (zombie)  X (deader)   x (dead)       K (wakekill) W (waking)
      SCHED Scheduling policy (0=other, 1=fifo, 2=rr, 3=batch, 4=iso, 5=idle)
      STAT  Process state (S) plus:
            < high priority          N low priority L locked memory
            s session leader         + foreground   l multithreaded
      STIME Start time of process in hh:mm (size :19 shows yyyy-mm-dd hh:mm:ss)
      SZ    Memory Size (4k pages needed to completely swap out process)
      TIME  CPU time consumed                 TTY     Controlling terminal
      UID   User id                           USER    User name
      VSZ   Virtual memory size (1k units)    %VSZ    VSZ as % of physical memory
      WCHAN Waiting in kernel for

config TOP
  bool "top"
  default y
  help
    usage: top [-m] [ -d seconds ] [ -n iterations ]

    Provide a view of process activity in real time.
    Keys
       N/M/P/T show CPU usage, sort by pid/mem/cpu/time
       S       show memory
       R       reverse sort
       H       toggle threads
       C,1     toggle SMP
       Q,^C    exit

    Options
       -n Iterations before exiting
       -d Delay between updates
       -m Same as 's' key

# Requires CONFIG_IRQ_TIME_ACCOUNTING in the kernel for /proc/$$/io
config IOTOP
  bool "iotop"
  default y
  help
    usage: iotop [-Aako]

    Rank processes by I/O.

    -A	All I/O, not just disk
    -a	Accumulated I/O (not percentage)
    -k	Kilobytes
    -o	Only show processes doing I/O

    Cursor left/right to change sort, space to update, Q to exit.

config TOP_COMMON
  bool
  default y
  help
    usage: COMMON [-bq] [-n NUMBER] [-d SECONDS] [-p PID,] [-u USER,]
    -b	Batch mode (no tty)
    -d	Delay SECONDS between each cycle (default 3)
    -n	Exit after NUMBER iterations
    -p	Show these PIDs
    -u	Show these USERs
    -q	Quiet (no header lines)

config PGREP
  bool "pgrep"
  default y
  depends on PGKILL_COMMON
  help
    usage: pgrep [-cL] [-d DELIM] [-L SIGNAL] [PATTERN]

    Search for process(es). PATTERN is an extended regular expression checked
    against command names.

    -c	Show only count of matches
    -d	Use DELIM instead of newline
    -L	Send SIGNAL instead of printing name
    -l	Show command name

config PGKILL_COMMON
  bool
  default y
  help
    usage: pgrep [-fnovx] [-G GID,] [-g PGRP,] [-P PPID,] [-s SID,] [-t TERM,] [-U UID,] [-u EUID,]

    -f	Check full command line for PATTERN
    -G	Match real Group ID(s)
    -g	Match Process Group(s) (0 is current user)
    -n	Newest match only
    -o	Oldest match only
    -P	Match Parent Process ID(s)
    -s	Match Session ID(s) (0 for current)
    -t	Match Terminal(s)
    -U	Match real User ID(s)
    -u	Match effective User ID(s)
    -v	Negate the match
    -x	Match whole command (not substring)

config PKILL
  bool "pkill"
  default y
  help
    usage: pkill [-l SIGNAL] [PATTERN]

    -l	SIGNAL to send
    -V	verbose
*/

#define FOR_ps
#include "toys.h"

GLOBALS(
  union {
    struct {
      struct arg_list *G;
      struct arg_list *g;
      struct arg_list *U;
      struct arg_list *u;
      struct arg_list *t;
      struct arg_list *s;
      struct arg_list *p;
      struct arg_list *o;
      struct arg_list *P;
      struct arg_list *k;
    } ps;
    struct {
      long n;
      long d;
      struct arg_list *u;
      struct arg_list *p;
    } top;
    struct{
      char *L;
      struct arg_list *G;
      struct arg_list *g;
      struct arg_list *P;
      struct arg_list *s;
      struct arg_list *t;
      struct arg_list *U;
      struct arg_list *u;
      char *d;

      void *regexes;
      int signal;
      pid_t self;
    } pgrep;
  };

  struct sysinfo si;
  struct ptr_len gg, GG, pp, PP, ss, tt, uu, UU;
  unsigned width, height;
  dev_t tty;
  void *fields, *kfields;
  long long ticks, bits, ioread, iowrite, aioread, aiowrite;
  size_t header_len;
  int kcount, forcek, sortpos;
  int (*match_process)(long long *slot);
  void (*show_process)(void *tb);
)

struct strawberry {
  struct strawberry *next, *prev;
  short which, len, reverse;
  char *title;
  char forever[];
};

/* The slot[] array is mostly populated from /proc/$PID/stat (kernel proc.txt
 * table 1-4) but we shift and repurpose fields, with the result being: */

enum {
 SLOT_pid,      /*process id*/            SLOT_ppid,      // parent process id
 SLOT_pgrp,     /*process group*/         SLOT_sid,       // session id
 SLOT_ttynr,    /*tty the process uses*/  SLOT_ttypgrp,   // pgrp of the tty
 SLOT_flags,    /*task flags*/            SLOT_minflt,    // minor faults
 SLOT_cminflt,  /*minor faults+child*/    SLOT_majflt,    // major faults
 SLOT_cmajflt,  /*major faults+child*/    SLOT_utime,     // user+kernel jiffies
 SLOT_stime,    /*kernel mode jiffies*/   SLOT_cutime,    // utime+child
 SLOT_cstime,   /*stime+child*/           SLOT_priority,  // priority level
 SLOT_nice,     /*nice level*/            SLOT_numthreads,// thread count
 SLOT_vmlck,    /*locked memory*/         SLOT_starttime, // jiffies after boot
 SLOT_vsize,    /*virtual memory size*/   SLOT_rss,       // resident set size
 SLOT_rsslim,   /*limit in bytes on rss*/ SLOT_startcode, // code segment addr
 SLOT_endcode,  /*code segment address*/  SLOT_startstack,// stack address
 SLOT_esp,      /*task stack pointer*/    SLOT_eip,       // instruction pointer
 SLOT_iobytes,  /*All I/O bytes*/         SLOT_diobytes,  // disk I/O bytes
 SLOT_utime2,   /*relative utime (top)*/  SLOT_uid,       // user id
 SLOT_ruid,     /*real user id*/          SLOT_gid,       // group id
 SLOT_rgid,     /*real group id*/         SLOT_exitsig,   // sent to parent
 SLOT_taskcpu,  /*CPU running on*/        SLOT_rtprio,    // realtime priority
 SLOT_policy,   /*man sched_setscheduler*/SLOT_blkioticks,// IO wait time
 SLOT_gtime,    /*guest jiffies of task*/ SLOT_cgtime,    // gtime+child
 SLOT_startbss, /*data/bss address*/      SLOT_endbss,    // end addr data+bss
 SLOT_upticks,  /*46-19 (divisor for %)*/ SLOT_argv0len,  // argv[0] length
 SLOT_uptime,   /*si.uptime @read time*/  SLOT_vsz,       // Virtual mem Size
 SLOT_rss2,     /*Resident Set Size*/     SLOT_shr,       // Shared memory
 SLOT_rchar,    /*All bytes read*/        SLOT_wchar,     // All bytes written
 SLOT_rbytes,   /*Disk bytes read*/       SLOT_wbytes,    // Disk bytes written
 SLOT_swap,     /*Swap pages used*/
};

// Data layout in toybuf
struct carveup {
  long long slot[55];       // data from /proc
  unsigned short offset[5]; // offset of fields in str[] (skip name, always 0)
  char state;
  char str[];               // name, tty, command, wchan, attr, cmdline
};

// TODO: Android uses -30 for LABEL, but ideally it would auto-size.
// 64|slot means compare as string when sorting
struct typography {
  char *name;
  signed char width, slot;
} static const typos[] = TAGGED_ARRAY(PS,
  // Numbers
  {"PID", 5, SLOT_pid}, {"PPID", 5, SLOT_ppid}, {"PRI", 3, SLOT_priority},
  {"NI", 3, SLOT_nice}, {"ADDR", 4+sizeof(long), SLOT_eip},
  {"SZ", 5, SLOT_vsize}, {"RSS", 5, SLOT_rss}, {"PGID", 5, SLOT_pgrp},
  {"VSZ", 6, SLOT_vsize}, {"MAJFL", 6, SLOT_majflt}, {"MINFL", 6, SLOT_minflt},
  {"PR", 2, SLOT_priority}, {"PSR", 3, SLOT_taskcpu},
  {"RTPRIO", 6, SLOT_rtprio}, {"SCH", 3, SLOT_policy}, {"CPU", 3, SLOT_taskcpu},

  // String fields
  {"COMM", -15, -1}, {"TTY", -8, -2}, {"WCHAN", -6, -3}, {"LABEL", -30, -4},
  {"COMMAND", -27, -5}, {"CMDLINE", -27, -6}, {"ARGS", -27, -6},
  {"NAME", -15, -6}, {"CMD", -27, -1},

  // user/group
  {"UID", 5, SLOT_uid}, {"USER", -8, 64|SLOT_uid}, {"RUID", 4, SLOT_ruid},
  {"RUSER", -8, 64|SLOT_ruid}, {"GID", 8, SLOT_gid}, {"GROUP", -8, 64|SLOT_gid},
  {"RGID", 4, SLOT_rgid}, {"RGROUP", -8, 64|SLOT_rgid},

  // clock displays
  {"TIME", 8, SLOT_utime}, {"ELAPSED", 11, SLOT_starttime},
  {"TIME+", 9, SLOT_utime},

  // Percentage displays
  {"C", 1, SLOT_utime2}, {"%VSZ", 5, SLOT_vsize}, {"%MEM", 5, SLOT_rss},
  {"%CPU", 4, SLOT_utime2},

  // human_readable
  {"VIRT", 4, SLOT_vsz}, {"RES", 4, SLOT_rss2},
  {"SHR", 4, SLOT_shr}, {"READ", 6, SLOT_rchar}, {"WRITE", 6, SLOT_wchar},
  {"IO", 6, SLOT_iobytes}, {"DREAD", 6, SLOT_rbytes},
  {"DWRITE", 6, SLOT_wbytes}, {"SWAP", 6, SLOT_swap}, {"DIO", 6, SLOT_diobytes},

  // Misc
  {"STIME", 5, SLOT_starttime}, {"F", 1, 64|SLOT_flags}, {"S", -1, 64},
  {"STAT", -5, 64},


);

// Return 0 to discard, nonzero to keep
static int shared_match_process(long long *slot)
{
  struct ptr_len match[] = {
    {&TT.gg, SLOT_gid}, {&TT.GG, SLOT_rgid}, {&TT.pp, SLOT_pid},
    {&TT.PP, SLOT_ppid}, {&TT.ss, SLOT_sid}, {&TT.tt, SLOT_ttynr},
    {&TT.uu, SLOT_uid}, {&TT.UU, SLOT_ruid}
  };
  int i, j;
  long *ll = 0;

  // Do we have -g -G -p -P -s -t -u -U options selecting processes?
  for (i = 0; i < ARRAY_LEN(match); i++) {
    struct ptr_len *mm = match[i].ptr;
    if (mm->len) {
      ll = mm->ptr;
      for (j = 0; j<mm->len; j++) if (ll[j] == slot[match[i].len]) return 1;
    }
  }

  return ll ? 0 : -1;
}


// Return 0 to discard, nonzero to keep
static int ps_match_process(long long *slot)
{
  int i = shared_match_process(slot);

  if (i>0) return 1;
  // If we had selections and didn't match them, don't display
  if (!i) return 0;

  // Filter implicit categories for other display types
  if ((toys.optflags&(FLAG_a|FLAG_d)) && slot[SLOT_sid]==*slot) return 0;
  if ((toys.optflags&FLAG_a) && !slot[SLOT_ttynr]) return 0;
  if (!(toys.optflags&(FLAG_a|FLAG_d|FLAG_A|FLAG_e))
      && TT.tty!=slot[SLOT_ttynr]) return 0;

  return 1;
}

// Convert field to string representation
static char *string_field(struct carveup *tb, struct strawberry *field)
{
  char *buf = toybuf+sizeof(toybuf)-260, *out = buf, *s;
  int which = field->which, sl = typos[which].slot;
  long long *slot = tb->slot, ll = (sl >= 0) ? slot[sl&63] : 0;

  // numbers, mostly from /proc/$PID/stat
  if (which <= PS_CPU) {
    char *fmt = "%lld";

    if (which==PS_PRI) ll = 39-ll;
    if (which==PS_ADDR) fmt = "%llx";
    else if (which==PS_SZ) ll >>= 12;
    else if (which==PS_RSS) ll <<= 2;
    else if (which==PS_VSZ) ll >>= 10;
    else if (which==PS_PR && ll<-9) fmt="RT";
    else if (which==PS_RTPRIO && ll == 0) fmt="-";
    sprintf(out, fmt, ll);

  // String fields
  } else if (sl < 0) {
    if (slot[SLOT_argv0len])
      tb->str[tb->offset[4]+slot[SLOT_argv0len]] = (which==PS_NAME) ? 0 : ' ';
    out = tb->str;
    sl *= -1;
    if (--sl) out += tb->offset[--sl];
    if (which==PS_ARGS)
      for (s = out; *s && *s != ' '; s++) if (*s == '/') out = s+1;
    if (which>=PS_COMMAND && !*out) sprintf(out = buf, "[%s]", tb->str);

  // user/group
  } else if (which <= PS_RGROUP) {
    sprintf(out, "%lld", ll);
    if (sl&64) {
      if (which > PS_RUSER) {
        struct group *gr = getgrgid(ll);

        if (gr) out = gr->gr_name;
      } else {
        struct passwd *pw = getpwuid(ll);

        if (pw) out = pw->pw_name;
      }
    }

  // Clock displays
  } else if (which <= PS_TIME_) {
    int unit = 60, pad = 2, j = TT.ticks; 
    time_t seconds;

    if (which!=PS_TIME_) unit *= 60*24;
    else pad = 0;
    // top adjusts slot[SLOT_upticks], we want original meaning.
    if (which==PS_ELAPSED) ll = (slot[SLOT_uptime]*j)-slot[SLOT_starttime];
    seconds = ll/j;

    // Output days-hours:mins:secs, skipping non-required fields with zero
    // TIME has 3 required fields, ETIME has 2. (Posix!) TIME+ is from top
    for (s = 0, j = 2*(which==PS_TIME_); j<4; j++) {
      if (!s && (seconds>unit || j == 1+(which!=PS_TIME))) s = out;
      if (s) {
        s += sprintf(s, j ? "%0*ld": "%*ld", pad, (long)(seconds/unit));
        pad = 2;
        if ((*s = "-::"[j])) s++;
      }
      seconds %= unit;
      unit /= j ? 60 : 24;
    }
    if (which==PS_TIME_ && s-out<8)
      sprintf(s, ".%02lld", (100*(ll%TT.ticks))/TT.ticks);

  // Percentage displays
  } else if (which <= PS__CPU) {
    ll = slot[sl&63]*1000;
    if (which==PS__VSZ || which==PS__MEM)
      ll /= TT.si.totalram/((which==PS__VSZ) ? 1024 : 4096);
    else if (slot[SLOT_upticks]) ll /= slot[SLOT_upticks];
    sl = ll;
    if (which==PS_C) sl += 5;
    sprintf(out, "%d", sl/10);
    if (which!=PS_C && sl<1000) sprintf(out+strlen(out), ".%d", sl%10);

  // Human readable
  } else if (which <= PS_DIO) {
    ll = slot[typos[which].slot];
    if (which <= PS_SHR) ll *= sysconf(_SC_PAGESIZE);
    if (TT.forcek) sprintf(out, "%lldk", ll/1024);
    else human_readable(out, ll, 0);

  // Posix doesn't specify what flags should say. Man page says
  // 1 for PF_FORKNOEXEC and 4 for PF_SUPERPRIV from linux/sched.h
  } else if (which==PS_F) sprintf(out, "%llo", (slot[SLOT_flags]>>6)&5);
  else if (which==PS_S || which==PS_STAT) {
    s = out;
    *s++ = tb->state;
    if (which==PS_STAT) {
      // TODO l = multithreaded
      if (slot[SLOT_nice]<0) *s++ = '<';
      else if (slot[SLOT_nice]>0) *s++ = 'N';
      if (slot[SLOT_sid]==*slot) *s++ = 's';
      if (slot[SLOT_vmlck]) *s++ = 'L';
      if (slot[SLOT_ttypgrp]==*slot) *s++ = '+';
    } 
    *s = 0;
  } else if (which==PS_STIME) {
    time_t t = time(0)-slot[SLOT_uptime]+slot[SLOT_starttime]/TT.ticks;

    // Padding behavior's a bit odd: default field size is just hh:mm.
    // Increasing stime:size reveals more data at left until full,
    // so move start address so yyyy-mm-dd hh:mm revealed on left at :16,
    // then add :ss on right for :19.
    strftime(out, 260, "%F %T", localtime(&t));
    out = out+strlen(out)-3-abs(field->len);
    if (out<buf) out = buf;

  } else if (CFG_TOYBOX_DEBUG) error_exit("bad which %d", which);

  return out;
}

// Display process data that get_ps() read from /proc, formatting with TT.fields
static void show_ps(struct carveup *tb)
{
  struct strawberry *field;
  int pad, len, width = TT.width;

  // Loop through fields to display
  for (field = TT.fields; field; field = field->next) {
    char *out = string_field(tb, field);

    // Output the field, appropriately padded
    if (field != TT.fields) {
      putchar(' ');
      width--;
    }
    len = width;
    pad = 0;
    if (field->next || field->len>0)
      len = abs(pad = width<abs(field->len) ? width : field->len);

    if (TT.tty) width -= draw_trim(out, pad, len);
    else width -= printf("%*.*s", pad, len, out);
    if (!width) break;
  }
  xputc('\n');
}

// dirtree callback: read data about process to display, store, or discard it.
// Fills toybuf with struct carveup and either DIRTREE_SAVEs a copy to ->extra
// (in -k mode) or calls show_ps on toybuf (no malloc/copy/free there).
static int get_ps(struct dirtree *new)
{
  struct {
    char *name;
    long long bits;
  } fetch[] = {
    {"fd/", _PS_TTY}, {"wchan", _PS_WCHAN}, {"attr/current", _PS_LABEL},
    {"exe", _PS_COMMAND}, {"cmdline", _PS_CMDLINE|_PS_ARGS|_PS_NAME}
  };
  struct carveup *tb = (void *)toybuf;
  long long *slot = tb->slot;
  char *name, *s, *buf = tb->str, *end = 0;
  int i, j, fd;
  off_t len;

  // Recurse one level into /proc children, skip non-numeric entries
  if (!new->parent)
    return DIRTREE_RECURSE|DIRTREE_SHUTUP|(DIRTREE_SAVE*!TT.show_process);

  memset(slot, 0, sizeof(tb->slot));
  if (!(*slot = atol(new->name))) return 0;
  fd = dirtree_parentfd(new);

  len = 2048;
  sprintf(buf, "%lld/stat", *slot);
  if (!readfileat(fd, buf, buf, &len)) return 0;

  // parse oddball fields (name and state). Name can have embedded ')' so match
  // _last_ ')' in stat (although VFS limits filenames to 255 bytes max).
  // All remaining fields should be numeric.
  if (!(name = strchr(buf, '('))) return 0;
  for (s = ++name; *s; s++) if (*s == ')') end = s;
  if (!end || end-name>255) return 0;

  // Parse numeric fields (starting at 4th field in slot[SLOT_ppid])
  if (1>sscanf(s = end, ") %c%n", &tb->state, &i)) return 0;
  for (j = 1; j<50; j++) if (1>sscanf(s += i, " %lld%n", slot+j, &i)) break;

  // Now we've read the data, move status and name right after slot[] array,
  // and convert low chars to ? for non-tty display while we're at it.
  for (i = 0; i<end-name; i++)
    if ((tb->str[i] = name[i]) < ' ')
      if (!TT.tty) tb->str[i] = '?';
  buf = tb->str+i;
  *buf++ = 0;
  len = sizeof(toybuf)-(buf-toybuf);

  // save uid, ruid, gid, gid, and rgid int slots 31-34 (we don't use sigcatch
  // or numeric wchan, and the remaining two are always zero), and vmlck into
  // 18 (which is "obsolete, always 0" from stat)
  slot[SLOT_uid] = new->st.st_uid;
  slot[SLOT_gid] = new->st.st_gid;

  // TIME and TIME+ use combined value, ksort needs 'em added.
  slot[SLOT_utime] += slot[SLOT_stime];
  slot[SLOT_utime2] = slot[SLOT_utime];

  // If RGROUP RUSER STAT RUID RGID SWAP happening, or -G or -U, parse "status"
  // and save ruid, rgid, and vmlck.
  if ((TT.bits&(_PS_RGROUP|_PS_RUSER|_PS_STAT|_PS_RUID|_PS_RGID|_PS_SWAP
               |_PS_IO|_PS_DIO)) || TT.GG.len || TT.UU.len)
  {
    off_t temp = len;

    sprintf(buf, "%lld/status", *slot);
    if (!readfileat(fd, buf, buf, &temp)) *buf = 0;
    s = strafter(buf, "\nUid:");
    slot[SLOT_ruid] = s ? atol(s) : new->st.st_uid;
    s = strafter(buf, "\nGid:");
    slot[SLOT_rgid] = s ? atol(s) : new->st.st_gid;
    if ((s = strafter(buf, "\nVmLck:"))) slot[SLOT_vmlck] = atoll(s);
    if ((s = strafter(buf, "\nVmSwap:"))) slot[SLOT_swap] = atoll(s);
  }

  // Do we need to read "io"?
  if (TT.bits&(_PS_READ|_PS_WRITE|_PS_DREAD|_PS_DWRITE|_PS_IO|_PS_DIO)) {
    off_t temp = len;

    sprintf(buf, "%lld/io", *slot);
    if (!readfileat(fd, buf, buf, &temp)) *buf = 0;
    if ((s = strafter(buf, "rchar:"))) slot[SLOT_rchar] = atoll(s);
    if ((s = strafter(buf, "wchar:"))) slot[SLOT_wchar] = atoll(s);
    if ((s = strafter(buf, "read_bytes:"))) slot[SLOT_rbytes] = atoll(s);
    if ((s = strafter(buf, "write_bytes:"))) slot[SLOT_wbytes] = atoll(s);
    slot[SLOT_iobytes] = slot[SLOT_rchar]+slot[SLOT_wchar]+slot[SLOT_swap];
    slot[SLOT_diobytes] = slot[SLOT_rbytes]+slot[SLOT_wbytes]+slot[SLOT_swap];
  }

  // We now know enough to skip processes we don't care about.
  if (TT.match_process && !TT.match_process(slot)) return 0;

  // /proc data is generated as it's read, so for maximum accuracy on slow
  // systems (or ps | more) we re-fetch uptime as we fetch each /proc line.
  sysinfo(&TT.si);
  slot[SLOT_uptime] = TT.si.uptime;
  slot[SLOT_upticks] = slot[SLOT_uptime]*TT.ticks - slot[SLOT_rss];

  // Do we need to read "statm"?
  if (TT.bits&(_PS_VIRT|_PS_RES|_PS_SHR)) {
    off_t temp = len;

    sprintf(buf, "%lld/statm", *slot);
    if (!readfileat(fd, buf, buf, &temp)) *buf = 0;
    
    for (s = buf, i=0; i<3; i++)
      if (!sscanf(s, " %lld%n", slot+SLOT_vsz+i, &j)) slot[SLOT_vsz+i] = 0;
      else s += j;
  }

  // Fetch string data while parentfd still available, appending to buf.
  // (There's well over 3k of toybuf left. We could dynamically malloc, but
  // it'd almost never get used, querying length of a proc file is awkward,
  // fixed buffer is nommu friendly... Wait for somebody to complain. :)
  slot[SLOT_argv0len] = 0;
  for (j = 0; j<ARRAY_LEN(fetch); j++) { 
    tb->offset[j] = buf-(tb->str);
    if (!(TT.bits&fetch[j].bits)) {
      *buf++ = 0;
      continue;
    }

    // Determine remaining space, reserving minimum of 256 bytes/field and
    // 260 bytes scratch space at the end (for output conversion later).
    len = sizeof(toybuf)-(buf-toybuf)-260-256*(ARRAY_LEN(fetch)-j);
    sprintf(buf, "%lld/%s", *slot, fetch[j].name);

    // For cmdline we readlink instead of read contents
    if (j==3) {
      if ((len = readlinkat(fd, buf, buf, len))>0) buf[len] = 0;
      else *buf = 0;

    // If it's not the TTY field, data we want is in a file.
    // Last length saved in slot[] is command line (which has embedded NULs)
    } else if (!j) {
      int rdev = slot[SLOT_ttynr];
      struct stat st;

      // Call no tty "?" rather than "0:0".
      strcpy(buf, "?");
      if (rdev) {
        // Can we readlink() our way to a name?
        for (i = 0; i<3; i++) {
          sprintf(buf, "%lld/fd/%i", *slot, i);
          if (!fstatat(fd, buf, &st, 0) && S_ISCHR(st.st_mode)
            && st.st_rdev == rdev && 0<(len = readlinkat(fd, buf, buf, len)))
          {
            buf[len] = 0;
            break;
          }
        }

        // Couldn't find it, try all the tty drivers.
        if (i == 3) {
          FILE *fp = fopen("/proc/tty/drivers", "r");
          int tty_major = 0, maj = major(rdev), min = minor(rdev);

          if (fp) {
            while (fscanf(fp, "%*s %256s %d %*s %*s", buf, &tty_major) == 2) {
              // TODO: we could parse the minor range too.
              if (tty_major == maj) {
                sprintf(buf+strlen(buf), "%d", min);
                if (!stat(buf, &st) && S_ISCHR(st.st_mode) && st.st_rdev==rdev)
                  break;
              }
              tty_major = 0;
            }
            fclose(fp);
          }

          // Really couldn't find it, so just show major:minor.
          if (!tty_major) sprintf(buf, "%d:%d", maj, min);
        }

        s = buf;
        if (strstart(&s, "/dev/")) memmove(buf, s, strlen(s)+1);
      }

    // Data we want is in a file.
    // Last length saved in slot[] is command line (which has embedded NULs)
    } else {

      // When command has no arguments, don't space over the NUL
      if (readfileat(fd, buf, buf, &len) && len>0) {
        int temp = 0;

        if (buf[len-1]=='\n') buf[--len] = 0;

        // Turn NUL to space, other low ascii to ? (in non-tty mode)
        for (i=0; i<len; i++) {
          char c = buf[i];

          if (!c) {
            if (!temp) temp = i;
            c = ' ';
          } else if (!TT.tty && c<' ') c = '?';
          buf[i] = c;
        }
        len = temp; // position of _first_ NUL
      } else *buf = len = 0;
      // Store end of argv[0] so NAME and CMDLINE can differ.
      slot[SLOT_argv0len] = len;
    }

    buf += strlen(buf)+1;
  }

  if (TT.show_process) {
    TT.show_process(tb);

    return 0;
  }

  // If we need to sort the output, add it to the list and return.
  s = xmalloc(buf-toybuf);
  new->extra = (long)s;
  memcpy(s, toybuf, buf-toybuf);
  TT.kcount++;

  return DIRTREE_SAVE;
}

static char *parse_ko(void *data, char *type, int length)
{
  struct strawberry *field;
  char *width, *title, *end, *s;
  int i, j, k;

  // Get title, length of title, type, end of type, and display width

  // Chip off =name to display
  if ((end = strchr(type, '=')) && length>(end-type)) {
    title = end+1;
    length -= (end-type)+1;
  } else {
    end = type+length;
    title = 0;
  }

  // Chip off :width to display
  if ((width = strchr(type, ':')) && width<end) {
    if (!title) length = width-type;
  } else width = 0;

  // Allocate structure, copy title
  field = xzalloc(sizeof(struct strawberry)+(length+1)*!!title);
  if (title) {
    memcpy(field->title = field->forever, title, length);
    field->title[field->len = length] = 0;
  }

  if (width) {
    field->len = strtol(++width, &title, 10);
    if (!isdigit(*width) || title != end) return title;
    end = --width;
  }

  // Find type
  if (*(struct strawberry **)data == TT.kfields) {
    field->reverse = 1;
    if (*type == '-') field->reverse = -1;
    else if (*type != '+') type--;
    type++;
  }
  for (i = 0; i<ARRAY_LEN(typos); i++) {
    field->which = i;
    for (j = 0; j<2; j++) {
      if (!j) s = typos[i].name;
      // posix requires alternate names for some fields
      else if (-1==(k = stridx((char []){PS_NI, PS_SCH, PS_ELAPSED, PS__CPU,
        PS_VSZ, PS_USER, 0}, i))) continue;
      else
        s = ((char *[]){"NICE", "SCHED", "ETIME", "PCPU", "VSIZE", "UNAME"})[k];

      if (!strncasecmp(type, s, end-type) && strlen(s)==end-type) break;
    }
    if (j!=2) break;
  }
  if (i==ARRAY_LEN(typos)) return type;
  if (!field->title) field->title = typos[field->which].name;
  if (!field->len) field->len = typos[field->which].width;
  else if (typos[field->which].width<0) field->len *= -1;
  dlist_add_nomalloc(data, (void *)field);

  // Print padded header for -o.
  if (*(struct strawberry **)data == TT.fields) {
    TT.header_len +=
      snprintf(toybuf + TT.header_len, sizeof(toybuf) - TT.header_len,
               " %*s" + (field == TT.fields), field->len, field->title);
    TT.bits |= 1LL<<field->which;
  }

  return 0;
}

// Parse -p -s -t -u -U -g -G
static char *parse_rest(void *data, char *str, int len)
{
  struct ptr_len *pl = (struct ptr_len *)data;
  long *ll = pl->ptr;
  char *end;
  int num = 0;

  // Allocate next chunk of data
  if (!(15&pl->len))
    ll = pl->ptr = xrealloc(pl->ptr, sizeof(long)*(pl->len+16));

  // Parse numerical input
  if (isdigit(*str)) {
    ll[pl->len] = xstrtol(str, &end, 10);
    if (end==(len+str)) num++;
  }

  if (pl==&TT.pp || pl==&TT.ss) {
    if (num && ll[pl->len]>0) {
      pl->len++;

      return 0;
    }
  } else if (pl==&TT.tt) {
    // -t pts = 12,pts/12 tty = /dev/tty2,tty2,S0
    if (!num) {
      if (strstart(&str, strcpy(toybuf, "/dev/"))) len -= 5;
      if (strstart(&str, "pts/")) {
        len -= 4;
        num++;
      } else if (strstart(&str, "tty")) len -= 3;
    }
    if (len<256 && (!(end = strchr(str, '/')) || end-str>len)) {
      struct stat st;

      end = toybuf + sprintf(toybuf, "/dev/%s", num ? "pts/" : "tty");
      memcpy(end, str, len);
      end[len] = 0;
      xstat(toybuf, &st);
      ll[pl->len++] = st.st_rdev;

      return 0;
    }
  } else if (len<255) {
    char name[256];

    if (num) {
      pl->len++;

      return 0;
    }

    memcpy(name, str, len);
    name[len] = 0;
    if (pl==&TT.gg || pl==&TT.GG) {
      struct group *gr = getgrnam(name);
      if (gr) {
        ll[pl->len++] = gr->gr_gid;

        return 0;
      }
    } else if (pl==&TT.uu || pl==&TT.UU) {
      struct passwd *pw = getpwnam(name);
      if (pw) {
        ll[pl->len++] = pw->pw_uid;

        return 0;
      }
    }
  }

  // Return error
  return str;
}

// sort for -k
static int ksort(void *aa, void *bb)
{
  struct strawberry *field;
  struct carveup *ta = *(struct carveup **)aa, *tb = *(struct carveup **)bb;
  int ret = 0, slot;

  for (field = TT.kfields; field && !ret; field = field->next) {
    slot = typos[field->which].slot;

    // Can we do numeric sort?
    if (!(slot&64)) {
      if (ta->slot[slot]<tb->slot[slot]) ret = -1;
      if (ta->slot[slot]>tb->slot[slot]) ret = 1;
    }

    // fallback to string sort
    if (!ret) {
      memccpy(toybuf, string_field(ta, field), 0, 2048);
      toybuf[2048] = 0;
      ret = strcmp(toybuf, string_field(tb, field));
    }
    ret *= field->reverse;
  }

  return ret;
}

static struct carveup **collate(int count, struct dirtree *dt,
  int (*sort)(void *a, void *b))
{
  struct dirtree *temp;
  struct carveup **tbsort = xmalloc(count*sizeof(struct carveup *));
  int i;

  // descend into child list
  *tbsort = (void *)dt;
  dt = dt->child;
  free(*tbsort);

  // populate array
  for (i = 0; i < count; i++) {
    temp = dt->next;
    tbsort[i] = (void *)dt->extra;
    free(dt);
    dt = temp;
  }

  return tbsort;
} 

static void shared_main(void)
{
  int i;

  TT.ticks = sysconf(_SC_CLK_TCK);
  if (!TT.width) {
    TT.width = 80;
    TT.height = 25;
    terminal_size(&TT.width, &TT.height);
  }

  // find controlling tty, falling back to /dev/tty if none
  for (i = 0; !TT.tty && i<4; i++) {
    struct stat st;
    int fd = i;

    if (i==3 && -1==(fd = open("/dev/tty", O_RDONLY))) break;

    if (isatty(fd) && !fstat(fd, &st)) TT.tty = st.st_rdev;
    if (i==3) close(fd);
  }
}

void ps_main(void)
{
  struct dirtree *dt;
  int i;

  if (toys.optflags&FLAG_w) TT.width = 99999;
  shared_main();

  // parse command line options other than -o
  comma_args(TT.ps.P, &TT.PP, "bad -P", parse_rest);
  comma_args(TT.ps.p, &TT.pp, "bad -p", parse_rest);
  comma_args(TT.ps.t, &TT.tt, "bad -t", parse_rest);
  comma_args(TT.ps.s, &TT.ss, "bad -s", parse_rest);
  comma_args(TT.ps.u, &TT.uu, "bad -u", parse_rest);
  comma_args(TT.ps.U, &TT.UU, "bad -U", parse_rest);
  comma_args(TT.ps.g, &TT.gg, "bad -g", parse_rest);
  comma_args(TT.ps.G, &TT.GG, "bad -G", parse_rest);
  comma_args(TT.ps.k, &TT.kfields, "bad -k", parse_ko);
  dlist_terminate(TT.kfields);

  // Parse manual field selection, or default/-f/-l, plus -Z,
  // constructing the header line in toybuf as we go.
  if (toys.optflags&FLAG_Z) {
    struct arg_list Z = { 0, "LABEL" };

    comma_args(&Z, &TT.fields, "-Z", parse_ko);
  }
  if (TT.ps.o) comma_args(TT.ps.o, &TT.fields, "bad -o field", parse_ko);
  else {
    struct arg_list al;

    al.next = 0;
    if (toys.optflags&FLAG_f)
      al.arg = "USER:8=UID,PID,PPID,C,STIME,TTY,TIME,CMD";
    else if (toys.optflags&FLAG_l)
      al.arg = "F,S,UID,PID,PPID,C,PRI,NI,ADDR,SZ,WCHAN,TTY,TIME,CMD";
    else if (CFG_TOYBOX_ON_ANDROID)
      al.arg = "USER,PID,PPID,VSIZE,RSS,WCHAN:10,ADDR:10=PC,S,CMDLINE";
    else al.arg = "PID,TTY,TIME,CMD";

    comma_args(&al, &TT.fields, 0, parse_ko);
  }
  dlist_terminate(TT.fields);
  printf("%s\n", toybuf);

  // misunderstand fields the flags say to
  if (toys.optflags&(FLAG_f|FLAG_n)) {
    struct strawberry *ever;

    for (ever = TT.fields; ever; ever = ever->next) {
      int alluc = ever->which;

      if ((toys.optflags&FLAG_f) && alluc==PS_CMD) alluc = PS_ARGS;
      if ((toys.optflags&FLAG_n) && alluc>=PS_UID && alluc<=PS_RGROUP
          && (typos[alluc].slot&64)) alluc--;
      if (alluc != ever->which) {
        TT.bits &= 1LL<<ever->which;
        TT.bits |= 1LL<<(ever->which = alluc);
      }
    }
  }

  if (!(toys.optflags&FLAG_k)) TT.show_process = (void *)show_ps;
  TT.match_process = ps_match_process;
  dt = dirtree_read("/proc", get_ps);

  if (toys.optflags&FLAG_k) {
    struct carveup **tbsort = collate(TT.kcount, dt, ksort);

    qsort(tbsort, TT.kcount, sizeof(struct carveup *), (void *)ksort);
    for (i = 0; i<TT.kcount; i++) {
      show_ps(tbsort[i]);
      free(tbsort[i]);
    }
    if (CFG_TOYBOX_FREE) free(tbsort);
  }

  if (CFG_TOYBOX_FREE) {
    free(TT.gg.ptr);
    free(TT.GG.ptr);
    free(TT.pp.ptr);
    free(TT.PP.ptr);
    free(TT.ss.ptr);
    free(TT.tt.ptr);
    free(TT.uu.ptr);
    free(TT.UU.ptr);
    llist_traverse(TT.fields, free);
  }
}

#define CLEANUP_ps
#define FOR_top
#include "generated/flags.h"

// select which of the -o fields to sort by
static void setsort(int pos)
{
  struct strawberry *field, *going2;
  int i = 0;

  if (pos<0) pos = 0;

  for (field = TT.fields; field; field = field->next) {
    if ((TT.sortpos = i++)<pos) continue;
    going2 = TT.kfields;
    going2->which = field->which;
    going2->len = field->len;
    break;
  }
}

// If we have both, adjust slot[deltas[]] to be relative to previous
// measurement rather than process start. Stomping old.data is fine
// because we free it after displaying.
static int merge_deltas(long long *oslot, long long *nslot)
{
  char deltas[] = {SLOT_utime2, SLOT_iobytes, SLOT_diobytes, SLOT_upticks,
                   SLOT_rchar, SLOT_wchar, SLOT_rbytes, SLOT_wbytes, SLOT_swap};
  int i;

  for (i = 0; i<ARRAY_LEN(deltas); i++)
    oslot[deltas[i]] = nslot[deltas[i]] - oslot[deltas[i]];

  return 1;
}

static void top_common(char *header,
  int (*filter)(long long *oslot, long long *nslot))
{
  struct timespec ts;
  long long timeout = 0, now;
  struct proclist {
    struct carveup **tb;
    int count;
  } plist[2], *plold, *plnew, old, new, mix;
  char scratch[16];
  unsigned tock = 0;
  int i, lines, done = 0;

  *scratch = 0;
  TT.top.d *= 1000;
  if (toys.optflags&FLAG_b) TT.width = TT.height = 99999;
  else {
    xset_terminal(0, 1, 0);
    sigatexit(tty_sigreset);
  }
  shared_main();

  comma_args(TT.top.u, &TT.uu, "bad -u", parse_rest);
  comma_args(TT.top.p, &TT.pp, "bad -p", parse_rest);

  TT.match_process = shared_match_process;
  memset(plist, 0, sizeof(plist));
  do {
    struct dirtree *dt = dirtree_read("/proc", get_ps);

    plold = plist+(tock++&1);
    plnew = plist+(tock&1);
    plnew->tb = collate(plnew->count = TT.kcount, dt, ksort);
    TT.kcount = 0;

    // First time, wait a quarter of a second to collect a little delta data.
    if (!plold->tb) {
      msleep(250);
      continue;
    }

    // Collate old and new into "mix", depends on /proc read in pid sort order
    old = *plold;
    new = *plnew;
    mix.tb = xmalloc((old.count+new.count)*sizeof(struct carveup));
    mix.count = 0;

    while (old.count || new.count) {
      struct carveup *otb = *old.tb, *ntb = *new.tb;

      // If we just have old, discard it.
      if (old.count && (!new.count || *otb->slot < *ntb->slot)) {
        old.tb++;
        old.count--;

        continue;
      }

      // If we just have new, use it verbatim
      if (!old.count || *otb->slot > *ntb->slot) mix.tb[mix.count] = ntb;
      else {
        // Keep or discard
        if (filter(otb->slot, ntb->slot)) {
          mix.tb[mix.count] = otb;
          mix.count++;
        }
        old.tb++;
        old.count--;
      }
      new.tb++;
      new.count--;
    }

    // Will will re-fetch no data before its time. - Mork calling Orson Welles
    for (;;) {
      char was, is, *pos;

      qsort(mix.tb, mix.count, sizeof(struct carveup *), (void *)ksort);
printf("cheese\n");
      if (!(toys.optflags&FLAG_b)) printf("\033[H\033[J");
      if (!(toys.optflags&FLAG_q)) {
        i = 0;
        strcpy(pos = toybuf, header);

        for (i=0, is = *pos; *pos; pos++) {
          was = is;
          is = *pos;
          if (isspace(was) && !isspace(is) && i++==TT.sortpos) pos[-1] = '[';
          if (!isspace(was) && isspace(is) && i==TT.sortpos+1) *pos = ']';
        }
        *pos = 0;
        printf("\033[7m%*.*s\033[0m\n\r",
          (toys.optflags&FLAG_b) ? 0 : -TT.width, TT.width, toybuf);

        if (!(toys.optflags&FLAG_b))
          terminal_probesize(&TT.width, &TT.height);
      }
      lines = TT.height-2;

      for (i=0; i<lines && i<mix.count; i++) {
        show_ps(mix.tb[i]);
        xputc('\r');
      }

      if (TT.top.n && !--TT.top.n) {
        done++;
        break;
      }

      // Get current time in miliseconds
      clock_gettime(CLOCK_MONOTONIC, &ts);
      now = ts.tv_sec*1000+ts.tv_nsec/1000000;
      if (timeout<=now) timeout += TT.top.d;
      if (timeout<=now) timeout = now+TT.top.d;

      i = scan_key_getsize(scratch, timeout-now, &TT.width, &TT.height);
      if (i==-1 || i==3 || toupper(i)=='Q') {
        done++;
        break;
      }
      if (i==-2) break;

      // Flush unknown escape sequences.
      if (i==27) while (0<scan_key_getsize(scratch, 0, &TT.width, &TT.height));
      else if (i==' ') {
        timeout = now;
        break;
      } else {
        i -= 256;
        if (i == KEY_LEFT) setsort(TT.sortpos-1);
        else if (i == KEY_RIGHT) setsort(TT.sortpos+1);
      }
      continue;
    }

    free(mix.tb);
    for (i=0; i<plold->count; i++) free(plold->tb[i]);
    free(plold->tb);
  } while (!done);
  if (!(toys.optflags&FLAG_b)) tty_reset();
}

void top_main(void)
{
  struct arg_list al;
  char *header;

  // Display fields
  al.next = 0;
  al.arg = xstrdup("PID,USER,PR,NI,VIRT,RES,SHR,S,%CPU,%MEM,TIME+,CMDLINE");
  comma_args(&al, &TT.fields, 0, parse_ko);
  free(al.arg);
  dlist_terminate(TT.fields);
  header=xstrdup(toybuf);

  // Fallback sorts
  al.arg = xstrdup("-S,-%CPU,-ETIME,-PID");
  comma_args(&al, &TT.kfields, "bang", parse_ko);
  dlist_terminate(TT.kfields);
  setsort(8);

  top_common(header, merge_deltas);
}

#define CLEANUP_top
#define FOR_iotop
#include "generated/flags.h"

static int iotop_filter(long long *oslot, long long *nslot)
{
  if (!(toys.optflags&FLAG_a)) merge_deltas(oslot, nslot);

  return !(toys.optflags&FLAG_o) || oslot[SLOT_iobytes+!(toys.optflags&FLAG_A)];
}

void iotop_main(void)
{
  struct arg_list al;
  char *header, *d = "D"+!!(toys.optflags&FLAG_A);

  if (toys.optflags&FLAG_k) TT.forcek++;

  al.next = 0;
  al.arg = xmprintf("PID,PR,USER,%sREAD,%sWRITE,SWAP,%sIO,COMM", d, d, d);
  comma_args(&al, &TT.fields, 0, parse_ko);
  free(al.arg);
  dlist_terminate(TT.fields);
  header = strdup(toybuf);

  // Fallback sorts. First (dummy) field gets overwritten by setsort()
  al.arg = xmprintf("-S,-%sIO,-ETIME,-PID",d);
  comma_args(&al, &TT.kfields, 0, parse_ko);
  free(al.arg);
  dlist_terminate(TT.kfields);
  setsort(6);

  top_common(header, iotop_filter);
}

// pkill's plumbing wrap's pgrep's and thus mostly takes place in pgrep's flag
// context, so force pgrep's flags on even when building pkill standalone.
// (All the pgrep/pkill functions drop out when building ps standalone.)
#define FORCE_FLAGS
#define CLEANUP_iotop
#define FOR_pgrep
#include "generated/flags.h"

struct regex_list {
  struct regex_list *next;
  regex_t reg;
};

static void show_pgrep(struct carveup *tb)
{
  regmatch_t match;
  struct regex_list *reg;
  char *name = tb->str;

  // Never match ourselves.
  if (TT.pgrep.self == *tb->slot) return;

  if (toys.optflags&FLAG_f) name += tb->offset[4];

  if (TT.pgrep.regexes) {
    for (reg = TT.pgrep.regexes; reg; reg = reg->next) {
      if (regexec(&reg->reg, name, 1, &match, 0)) continue;
      if (toys.optflags&FLAG_x)
        if (match.rm_so || match.rm_eo!=strlen(name)) continue;
      break;
    }
    if ((toys.optflags&FLAG_v) ? !!reg : !reg) return;
  }

  // Repurpose a field for -c count
  TT.sortpos++;
  if (TT.pgrep.signal) {
    if (kill(*tb->slot, TT.pgrep.signal)) {
      char *s = num_to_sig(TT.pgrep.signal);

      if (!s) sprintf(s = toybuf, "%d", TT.pgrep.signal);
      perror_msg("%s->%lld", s, *tb->slot);
    }
  }
  if (!(toys.optflags&FLAG_c) && (!TT.pgrep.signal || TT.tty)) {
    printf("%lld", *tb->slot);
    if (toys.optflags&FLAG_l) printf(" %s", name);
    
    printf("%s", TT.pgrep.d ? TT.pgrep.d : "\n");
  }
}

static int pgrep_match_process(long long *slot)
{
  int match = shared_match_process(slot);

  return (toys.optflags&FLAG_v) ? !match : match;
}

void pgrep_main(void)
{
  char **arg;
  struct regex_list *reg;

  TT.pgrep.self = getpid();

  // No signal names start with "L", so no need for "L: " parsing.
  if (TT.pgrep.L && 1>(TT.pgrep.signal = sig_to_num(TT.pgrep.L)))
    error_exit("bad -L '%s'", TT.pgrep.L);

  comma_args(TT.pgrep.G, &TT.GG, "bad -G", parse_rest);
  comma_args(TT.pgrep.g, &TT.gg, "bad -g", parse_rest);
  comma_args(TT.pgrep.P, &TT.PP, "bad -P", parse_rest);
  comma_args(TT.pgrep.s, &TT.ss, "bad -s", parse_rest);
  comma_args(TT.pgrep.t, &TT.tt, "bad -t", parse_rest);
  comma_args(TT.pgrep.U, &TT.UU, "bad -U", parse_rest);
  comma_args(TT.pgrep.u, &TT.uu, "bad -u", parse_rest);

  if ((toys.optflags&(FLAG_x|FLAG_f)) ||
      !(toys.optflags&(FLAG_G|FLAG_g|FLAG_P|FLAG_s|FLAG_t|FLAG_U|FLAG_u)))
    if (!toys.optc) help_exit("No PATTERN");

  if (toys.optflags&FLAG_f) TT.bits |= _PS_CMDLINE;
  for (arg = toys.optargs; *arg; arg++) {
    reg = xmalloc(sizeof(struct regex_list));
    xregcomp(&reg->reg, *arg, REG_EXTENDED);
    reg->next = TT.pgrep.regexes;
    TT.pgrep.regexes = reg;
  }
  TT.match_process = pgrep_match_process;
  TT.show_process = (void *)show_pgrep;

  dirtree_read("/proc", get_ps);
  if (toys.optflags&FLAG_c) printf("%d\n", TT.sortpos);
  if (TT.pgrep.d) xputc('\n');
}

#define CLEANUP_pgrep
#define FOR_pkill
#include "generated/flags.h"

void pkill_main(void)
{
  if (!TT.pgrep.L) TT.pgrep.signal = SIGTERM;
  if (toys.optflags & FLAG_V) TT.tty = 1;
  pgrep_main();
}