sortformat.c

linux下获取一些环境信息的代码

      if(!ss) return "Unknown sort specifier.";
      snode = do_one_sort_spec(ss->spec);
      if(!snode) return "Unknown sort specifier.";
      snode->reverse = direction;
      endp = snode; while(endp->next) endp = endp->next;  /* find end */
      endp->next = sfn->s_cooked;
      sfn->s_cooked = snode;
      direction = 0;
      break;
    }
    walk++;
  }
}

/******************* high-level below here *********************/


/*
 * Used to parse option O lists. Option O is shared between
 * sorting and formatting. Users may expect one or the other.
 * The "broken" flag enables a really bad Unix98 misfeature.
 * Recursion is to preserve original order.
 */
static const char *parse_O_option(sf_node *sfn){
  const char *err;     /* error code that could or did happen */

  if(sfn->next){
    err = parse_O_option(sfn->next);
    if(err) return err;
  }

  switch(sfn->sf_code){
    case SF_B_o: case SF_G_format: case SF_U_o: /*** format ***/
      err = format_parse(sfn);
      if(!err) already_parsed_format = 1;
      break;
    case SF_U_O:                                /*** format ***/
      /* Can have -l -f f u... set already_parsed_format like DEC does */
      if(already_parsed_format) return "option -O can not follow other format options.";
      err = format_parse(sfn);
      if(err) return err;
      already_parsed_format = 1;
      O_wrap(sfn,'u'); /* must wrap user format in default */
      break;
    case SF_B_O:                                /***  both  ***/
      if(have_gnu_sort || already_parsed_sort) err = "Multiple sort options.";
      else err = verify_short_sort(sfn->sf);
      if(!err){ /* success as sorting code */
        short_sort_parse(sfn);
        already_parsed_sort = 1;
        return NULL;
      }
      if(already_parsed_format){
        err = "option O is neither first format nor sort order.";
        break;
      }
      if(!format_parse(sfn)){ /* if success as format code */
        already_parsed_format = 1;
        O_wrap(sfn,'b'); /* must wrap user format in default */
        return NULL;
      }
      break;
    case SF_G_sort: case SF_B_m:                 /***  sort  ***/
      if(already_parsed_sort) err = "Multiple sort options.";
      else err = long_sort_parse(sfn);
      already_parsed_sort = 1;
      break;
    default:                                    /***  junk  ***/
      return "Bug: parse_O_option got weirdness!";
  }
  return err; /* could be NULL */
}


/************ Main parser calls this to save lists for later **********/
/* store data for later and return 1 if arg looks non-standard */
int defer_sf_option(const char *arg, int source){
  sf_node *sfn;
  char buf[16];
  int dist;
  const format_struct *fs;
  int need_item = 1;

  sfn = malloc(sizeof(sf_node));
  sfn->sf = malloc(strlen(arg)+1);
  strcpy(sfn->sf, arg);
  sfn->sf_code = source;
  sfn->s_cooked = NULL;
  sfn->f_cooked = NULL;
  sfn->next = sf_list;
  sf_list = sfn;

  if(source == SF_G_sort) have_gnu_sort = 1;

  /* Now try to find an excuse to ignore broken Unix98 parsing. */
  if(source != SF_U_o) return 1;    /* Wonderful! Already non-Unix98. */
  do{
    switch(*arg){
    case ' ': case ',': case '\0':  /* no \t\n\r support in Unix98 */
      if(need_item) return 1;       /* something wrong */
      need_item=1;
      break;
    case '=':
      if(need_item) return 1;       /* something wrong */
      return 0;                     /* broken Unix98 parsing is required */
    default:
      if(!need_item) break;
      need_item=0;
      dist = strcspn(arg,", =");
      if(dist>15) return 1;         /* something wrong, sort maybe? */
      strncpy(buf,arg,dist);   /* no '\0' on end */
      buf[dist] = '\0';        /* fix that problem */
      fs = search_format_array(buf);
      if(!fs) return 1;             /* invalid spec, macro or sort maybe? */
      if(fs->vendor) return 1;      /* Wonderful! Legal non-Unix98 spec. */
    }
  } while (*++arg);

  return 0;                         /* boring, Unix98 is no change */
}

/***** Since ps is not long-lived, the memory leak can be ignored. ******/
void reset_sortformat(void){
  sf_list = NULL;          /* deferred sorting and formatting */
  format_list = NULL;      /* digested formatting options */
  sort_list = NULL;        /* digested sorting options (redundant?) */
  have_gnu_sort = 0;
  already_parsed_sort = 0;
  already_parsed_format = 0;
}


/***** Search format_list for findme, then insert putme after findme. ****/
static int fmt_add_after(const char *findme, format_node *putme){
  format_node *walk;
  if(!strcmp(format_list->name, findme)){
    putme->next = format_list->next;
    format_list->next = putme;
    return 1; /* success */
  }
  walk = format_list;
  while(walk->next){
    if(!strcmp(walk->next->name, findme)){
      putme->next = walk->next->next;
      walk->next->next = putme;
      return 1; /* success */
    }
    walk = walk->next;
  }
  return 0; /* fail */
}

/******* Search format_list for findme, then delete it. ********/
static int fmt_delete(const char *findme){
  format_node *walk;
  format_node *old;
  if(!strcmp(format_list->name, findme)){
    old = format_list;
    format_list = format_list->next;
    free(old);
    return 1; /* success */
  }
  walk = format_list;
  while(walk->next){
    if(!strcmp(walk->next->name, findme)){
      old = walk->next;
      walk->next = walk->next->next;
      free(old);
      return 1; /* success */
    }
    walk = walk->next;
  }
  return 0; /* fail */
}


/************ Build a SysV format backwards. ***********/
#define PUSH(foo) (fn=do_one_spec(foo, NULL), fn->next=format_list, format_list=fn)
static const char *generate_sysv_list(void){
  format_node *fn;
  if((format_modifiers & FM_y) && !(format_flags & FF_Ul))
    return "Modifier -y without format -l makes no sense.";
  if(prefer_bsd_defaults){
    if(format_flags) PUSH("cmd");
    else PUSH("args");
    PUSH("bsdtime");
    if(!(format_flags & FF_Ul)) PUSH("stat");
  }else{
    if(format_flags & FF_Uf) PUSH("cmd");
    else PUSH("ucmd");
    PUSH("time");
  }
  PUSH("tname");  /* Unix98 says "TTY" here, yet "tty" produces "TT". */
  if(format_flags & FF_Uf) PUSH("stime");
  /* avoid duplicate columns from -FP and -Fly */
  if(format_modifiers & FM_F){
    /* if -FP take the Sun-style column instead (sorry about "sgi_p") */
    if(!(format_modifiers & FM_P)) PUSH("psr");  /* should be ENG */
    /* if -Fly take the ADDR-replacement RSS instead */
    if(!( (format_flags & FF_Ul) && (format_modifiers & FM_y) )) PUSH("rss");
  }
  if(format_flags & FF_Ul){
    PUSH("wchan");
  }
  /* since FM_y adds RSS anyway, don't do this hack when that is true */
  if( (format_flags & FF_Ul) && !(format_modifiers & FM_y) ){
    if(personality & PER_IRIX_l){ /* add "rss" then ':' here */
      PUSH("sgi_rss");
      fn = malloc(sizeof(format_node));
      fn->width = 1;
      fn->name = malloc(2);
      strcpy(fn->name, ":");
      fn->pr = NULL;     /* checked for */
      fn->need = 0;
      fn->vendor = AIX;   /* yes, for SGI weirdness */
      fn->flags = CF_PRINT_EVERY_TIME;
      fn->next = format_list;
      format_list=fn;
    }
  }
  if((format_modifiers & FM_F) || (format_flags & FF_Ul)){
    PUSH("sz");
  }
  if(format_flags & FF_Ul){
    if(format_modifiers & FM_y) PUSH("rss");
    else if(personality & (PER_ZAP_ADDR|PER_IRIX_l)) PUSH("sgi_p");
    else PUSH("addr_1");
  }
  if(format_modifiers & FM_c){
    PUSH("pri"); PUSH("class");
  }else if(format_flags & FF_Ul){
    PUSH("ni");
    if(personality & PER_IRIX_l) PUSH("priority");
    else /* is this good? */ PUSH("opri");
  }

  // FIXME TODO XXX -- this is a serious problem
  // These somehow got flipped around.
  // The bug is in procps-3.1.1, procps-990211, prior too?
  if((thread_flags & TF_U_L) && (format_flags & FF_Uf)) PUSH("nlwp");
  if( (format_flags & (FF_Uf|FF_Ul)) && !(format_modifiers & FM_c) ) PUSH("c");

  if(format_modifiers & FM_P) PUSH("psr");
  if(thread_flags & TF_U_L) PUSH("lwp");
  if(format_modifiers & FM_j){
    PUSH("sid");
    PUSH("pgid");
  }
  if(format_flags & (FF_Uf|FF_Ul)) PUSH("ppid");
  if(thread_flags & TF_U_T) PUSH("spid");
  PUSH("pid");
  if(format_flags & FF_Uf){
    if(personality & PER_SANE_USER) PUSH("user");
    else PUSH("uid_hack");
  }else if(format_flags & FF_Ul){
    PUSH("uid");
  }
  if(format_flags & FF_Ul){
    PUSH("s");
    if(!(format_modifiers & FM_y)) PUSH("f");
  }
  if(format_modifiers & FM_M){
    PUSH("label");  /* Mandatory Access Control */
  }
  return NULL;
}


/**************************************************************************
 * Used to parse option O lists. Option O is shared between
 * sorting and formatting. Users may expect one or the other.
 * The "broken" flag enables a really bad Unix98 misfeature.
 */
const char *process_sf_options(int localbroken){
  sf_node *sf_walk;

  if(personality & PER_BROKEN_o) localbroken = 1;
  if(personality & PER_GOOD_o)   localbroken = 0;
  broken = localbroken;
  if(sf_list){
    const char *err;
    err = parse_O_option(sf_list);
    if(err) return err;
  }

  if(format_list) printf("Bug: must reset the list first!\n");

  /* merge formatting info of sf_list into format_list here */
  sf_walk = sf_list;
  while(sf_walk){
    format_node *fmt_walk;
    fmt_walk = sf_walk->f_cooked;
    sf_walk->f_cooked = NULL;
    while(fmt_walk){   /* put any nodes onto format_list in opposite way */
      format_node *travler;
      travler = fmt_walk;
      fmt_walk = fmt_walk->next;
      travler->next = format_list;
      format_list = travler;
    }
    sf_walk = sf_walk->next;
  }

  /* merge sorting info of sf_list into sort_list here */
  sf_walk = sf_list;
  while(sf_walk){
    sort_node *srt_walk;
    srt_walk = sf_walk->s_cooked;
    sf_walk->s_cooked = NULL;
    while(srt_walk){   /* put any nodes onto sort_list in opposite way */
      sort_node *travler;
      travler = srt_walk;
      srt_walk = srt_walk->next;
      travler->next = sort_list;
      sort_list = travler;
    }
    sf_walk = sf_walk->next;
  }

  // Get somebody to explain how -L/-T is supposed to interact
  // with sorting. Do the threads remain grouped, with sorting
  // by process, or do the threads get sorted by themselves?
  if(sort_list && (thread_flags&TF_no_sort)){
    return "Tell [e-mail] what you expected.";
  }

  // If nothing else, try to use $PS_FORMAT before the default.
  if(!format_flags && !format_modifiers && !format_list){
    char *tmp;
    tmp = getenv("PS_FORMAT");  /* user override kills default */
    if(tmp && *tmp){
      const char *err;
      sf_node sfn;
      if(thread_flags&TF_must_use) return "Tell [e-mail] what you want. (-L/-T, -m/m/H, and $PS_FORMAT)";
      sfn.sf = tmp;
      sfn.f_cooked = NULL;
      err = format_parse(&sfn);
      if(!err){
        format_node *fmt_walk;
        fmt_walk = sfn.f_cooked;
        while(fmt_walk){   /* put any nodes onto format_list in opposite way */
          format_node *travler;
          travler = fmt_walk;
          fmt_walk = fmt_walk->next;
          travler->next = format_list;
          format_list = travler;
        }
        return NULL;
      }
      // FIXME: prove that this won't be hit on valid bogus-BSD options
      fprintf(stderr, "Warning: $PS_FORMAT ignored. (%s)\n", err);
    }
  }

  if(format_list){
    if(format_flags) return "Conflicting format options.";
    if(format_modifiers) return "Can't use output modifiers with user-defined output";
    if(thread_flags&TF_must_use) return "-L/-T with H/m/-m and -o/-O/o/O is nonsense";
    return NULL;
  }

  do{
    const char *spec;
    switch(format_flags){

    default:             return "Conflicting format options.";

    /* These can be NULL, which enables SysV list generation code. */
    case 0:              spec=NULL;           break;
    case FF_Uf | FF_Ul:  spec=sysv_fl_format; break;
    case FF_Uf:          spec=sysv_f_format;  break;
    case FF_Ul:          spec=sysv_l_format;  break;

    /* These are NOT REACHED for normal -j processing. */
    case FF_Uj:          spec=sysv_j_format;  break; /* Debian & Digital */
    case FF_Uj | FF_Ul:  spec="RD_lj";        break; /* Debian */
    case FF_Uj | FF_Uf:  spec="RD_fj";        break; /* Debian */

    /* These are true BSD options. */
    case FF_Bj:          spec=bsd_j_format;   break;
    case FF_Bl:          spec=bsd_l_format;   break;
    case FF_Bs:          spec=bsd_s_format;   break;
    case FF_Bu:          spec=bsd_u_format;   break;
    case FF_Bv:          spec=bsd_v_format;   break;

    /* These are old Linux options. Option m is overloaded. */
    case FF_LX:          spec="OL_X";         break;
    case FF_Lm:          spec="OL_m";         break;

    /* This is the sole FLASK security option. */
    case FF_Fc:          spec="FLASK_context"; break;

    }  /* end switch(format_flags) */

    // not just for case 0, since sysv_l_format and such may be NULL
    if(!spec) return generate_sysv_list();

    do{
      format_node *fmt_walk;
      fmt_walk = do_one_spec(spec, NULL); /* use override "" for no headers */
      while(fmt_walk){   /* put any nodes onto format_list in opposite way */
        format_node *travler;
        travler = fmt_walk;
        fmt_walk = fmt_walk->next;
        travler->next = format_list;
        format_list = travler;
      }
    }while(0);
  }while(0);

  do{
    format_node *fn;
    if(format_modifiers & FM_j){
      fn = do_one_spec("pgid", NULL);
      if(!fmt_add_after("PPID", fn)) if(!fmt_add_after("PID", fn))
        return "Internal error, no PID or PPID for -j option.";
      fn = do_one_spec("sid", NULL);
      if(!fmt_add_after("PGID", fn)) return "Lost my PGID!";
    }
    if(format_modifiers & FM_y){
      /* TODO: check for failure to do something, and complain if so */
      fmt_delete("F");
      fn = do_one_spec("rss", NULL);
      if(fmt_add_after("ADDR", fn)) fmt_delete("ADDR");
    }
    if(format_modifiers & FM_c){
      fmt_delete("%CPU"); fmt_delete("CPU"); fmt_delete("CP"); fmt_delete("C");
      fmt_delete("NI");
      fn = do_one_spec("class", NULL);
      if(!fmt_add_after("PRI", fn))
        return "Internal error, no PRI for -c option.";
      fmt_delete("PRI"); /* we want a different one */
      fn = do_one_spec("pri", NULL);
      if(!fmt_add_after("CLS", fn)) return "Lost my CLS!";
    }
    if(thread_flags & TF_U_T){
      fn = do_one_spec("spid", NULL);
      if(!fmt_add_after("PID", fn) && (thread_flags&TF_must_use))
        return "-T with H/-m/m but no PID for SPID to follow";
    }
    if(thread_flags & TF_U_L){
      fn = do_one_spec("lwp", NULL);
      if(fmt_add_after("SID",  fn)) goto did_lwp;
      if(fmt_add_after("SESS", fn)) goto did_lwp;
      if(fmt_add_after("PGID", fn)) goto did_lwp;
      if(fmt_add_after("PGRP", fn)) goto did_lwp;
      if(fmt_add_after("PPID", fn)) goto did_lwp;
      if(fmt_add_after("PID",  fn)) goto did_lwp;
      if(thread_flags&TF_must_use)
        return "-L with H/-m/m but no PID/PGID/SID/SESS for NLWP to follow";
did_lwp:
      fn = do_one_spec("nlwp", NULL);
      fmt_add_after("%CPU",  fn);
    }
    if(format_modifiers & FM_M){    // Mandatory Access Control, IRIX style
      fn = do_one_spec("label", NULL);
      fn->next=format_list;
      format_list=fn;
    }
    /* Do personality-specific translations not covered by format_flags.
     * Generally, these only get hit when personality overrides unix output.
     * That (mostly?) means the Digital and Debian personalities.
     */
    if((personality & PER_ZAP_ADDR) && (format_flags & FF_Ul)){
      fn = do_one_spec("sgi_p", NULL);
      if(fmt_add_after("ADDR", fn)) fmt_delete("ADDR");
    }
    if((personality & PER_SANE_USER) && (format_flags & FF_Uf)){
      fn = do_one_spec("user", NULL);
      if(fmt_add_after("UID", fn)) fmt_delete("UID");
    }
  }while(0);

  return NULL;
}