contrib/top/commands.c

   1 /*
   2  *  Top users/processes display for Unix
   3  *  Version 3
   4  *
   5  *  This program may be freely redistributed,
   6  *  but this entire comment MUST remain intact.
   7  *
   8  *  Copyright (c) 1984, 1989, William LeFebvre, Rice University
   9  *  Copyright (c) 1989, 1990, 1992, William LeFebvre, Northwestern University
  10  *
  11  * $FreeBSD: src/contrib/top/commands.c,v 1.4.6.1 2002/08/11 17:09:25 dwmalone Exp $
  12  * $DragonFly: src/contrib/top/commands.c,v 1.3 2006/02/15 12:54:36 corecode Exp $
  13  */
  14
  15 /*
  16  *  This file contains the routines that implement some of the interactive
  17  *  mode commands.  Note that some of the commands are implemented in-line
  18  *  in "main".  This is necessary because they change the global state of
  19  *  "top" (i.e.:  changing the number of processes to display).
  20  */
  21
  22 #include "os.h"
  23 #include <ctype.h>
  24 #include <signal.h>
  25 #include <unistd.h>
  26 #include <errno.h>
  27 #include <sys/time.h>
  28 #include <sys/resource.h>
  29
  30 #include "sigdesc.h"            /* generated automatically */
  31 #include "top.h"
  32 #include "boolean.h"
  33 #include "utils.h"
  34 #include "commands.h"
  35
  36 struct errs;
  37
  38 extern const char *copyright;
  39
  40 /* imported from screen.c */
  41 extern int overstrike;
  42
  43 static int err_compar(const void *, const void *);
  44 static const char *err_string(void);
  45 static int str_adderr(char *str, int len, int err);
  46 static int str_addarg(char *str, int len, char *arg, int first);
  47
  48 /*
  49  *  show_help() - display the help screen; invoked in response to
  50  *              either 'h' or '?'.
  51  */
  52
  53 void
  54 show_help(void)
  55 {
  56     printf("Top version %s, %s\n", version_string(), copyright);
  57     fputs("\n\n\
  58 A top users display for Unix\n\
  59 \n\
  60 These single-character commands are available:\n\
  61 \n\
  62 ^L      - redraw screen\n\
  63 q       - quit\n\
  64 h or ?  - help; show this text\n", stdout);
  65
  66     /* not all commands are availalbe with overstrike terminals */
  67     if (overstrike)
  68     {
  69         fputs("\n\
  70 Other commands are also available, but this terminal is not\n\
  71 sophisticated enough to handle those commands gracefully.\n\n", stdout);
  72     }
  73     else
  74     {
  75         fputs("\
  76 d       - change number of displays to show\n\
  77 e       - list errors generated by last \"kill\" or \"renice\" command\n\
  78 i       - toggle the displaying of idle processes\n\
  79 I       - same as 'i'\n\
  80 O       - only display threads\n\
  81 T       - toggle the displaying of threads\n\
  82 S       - toggle the displaying of system processes\n\
  83 k       - kill processes; send a signal to a list of processes\n\
  84 n or #  - change number of processes to display\n", stdout);
  85 #ifdef ORDER
  86         fputs("\
  87 o       - specify sort order (pri, size, res, cpu, time, thr)\n", stdout);
  88 #endif
  89         fputs("\
  90 r       - renice a process\n\
  91 s       - change number of seconds to delay between updates\n\
  92 u       - display processes for only one user (+ selects all users)\n\
  93 \n\
  94 \n", stdout);
  95     }
  96 }
  97
  98 /*
  99  *  Utility routines that help with some of the commands.
 100  */
 101
 102 char *
 103 next_field(char *str)
 104 {
 105     if ((str = strchr(str, ' ')) == NULL)
 106     {
 107         return(NULL);
 108     }
 109     *str = '\0';
 110     while (*++str == ' ') /* loop */;
 111
 112     /* if there is nothing left of the string, return NULL */
 113     /* This fix is dedicated to Greg Earle */
 114     return(*str == '\0' ? NULL : str);
 115 }
 116
 117 int
 118 scanint(char *str, int *intp)
 119 {
 120     register int val = 0;
 121     register char ch;
 122
 123     /* if there is nothing left of the string, flag it as an error */
 124     /* This fix is dedicated to Greg Earle */
 125     if (*str == '\0')
 126     {
 127         return(-1);
 128     }
 129
 130     while ((ch = *str++) != '\0')
 131     {
 132         if (isdigit(ch))
 133         {
 134             val = val * 10 + (ch - '0');
 135         }
 136         else if (isspace(ch))
 137         {
 138             break;
 139         }
 140         else
 141         {
 142             return(-1);
 143         }
 144     }
 145     *intp = val;
 146     return(0);
 147 }
 148
 149 /*
 150  *  Some of the commands make system calls that could generate errors.
 151  *  These errors are collected up in an array of structures for later
 152  *  contemplation and display.  Such routines return a string containing an
 153  *  error message, or NULL if no errors occurred.  The next few routines are
 154  *  for manipulating and displaying these errors.  We need an upper limit on
 155  *  the number of errors, so we arbitrarily choose 20.
 156  */
 157
 158 #define ERRMAX 20
 159
 160 struct errs             /* structure for a system-call error */
 161 {
 162     int  errnum;        /* value of errno (that is, the actual error) */
 163     char *arg;          /* argument that caused the error */
 164 };
 165
 166 static struct errs errs[ERRMAX];
 167 static int errcnt;
 168 static const char *err_toomany = " too many errors occurred";
 169 static const char *err_listem =
 170         " Many errors occurred.  Press `e' to display the list of errors.";
 171
 172 /* These macros get used to reset and log the errors */
 173 #define ERR_RESET   errcnt = 0
 174 #define ERROR(p, e) if (errcnt >= ERRMAX) \
 175                     { \
 176                         return(err_toomany); \
 177                     } \
 178                     else \
 179                     { \
 180                         errs[errcnt].arg = (p); \
 181                         errs[errcnt++].errnum = (e); \
 182                     }
 183
 184 /*
 185  *  err_string() - return an appropriate error string.  This is what the
 186  *      command will return for displaying.  If no errors were logged, then
 187  *      return NULL.  The maximum length of the error string is defined by
 188  *      "STRMAX".
 189  */
 190
 191 #define STRMAX 80
 192
 193 static const char *
 194 err_string(void)
 195 {
 196     struct errs *errp;
 197     int  cnt = 0;
 198     int  first = Yes;
 199     int  currerr = -1;
 200     int stringlen;              /* characters still available in "string" */
 201     static char string[STRMAX];
 202
 203     /* if there are no errors, return NULL */
 204     if (errcnt == 0)
 205     {
 206         return(NULL);
 207     }
 208
 209     /* sort the errors */
 210     qsort((char *)errs, errcnt, sizeof(struct errs), err_compar);
 211
 212     /* need a space at the front of the error string */
 213     string[0] = ' ';
 214     string[1] = '\0';
 215     stringlen = STRMAX - 2;
 216
 217     /* loop thru the sorted list, building an error string */
 218     while (cnt < errcnt)
 219     {
 220         errp = &(errs[cnt++]);
 221         if (errp->errnum != currerr)
 222         {
 223             if (currerr != -1)
 224             {
 225                 if ((stringlen = str_adderr(string, stringlen, currerr)) < 2)
 226                 {
 227                     return(err_listem);
 228                 }
 229                 (void) strcat(string, "; ");      /* we know there's more */
 230             }
 231             currerr = errp->errnum;
 232             first = Yes;
 233         }
 234         if ((stringlen = str_addarg(string, stringlen, errp->arg, first)) ==0)
 235         {
 236             return(err_listem);
 237         }
 238         first = No;
 239     }
 240
 241     /* add final message */
 242     stringlen = str_adderr(string, stringlen, currerr);
 243
 244     /* return the error string */
 245     return(stringlen == 0 ? err_listem : string);
 246 }
 247
 248 /*
 249  *  str_adderr(str, len, err) - add an explanation of error "err" to
 250  *      the string "str".
 251  */
 252
 253 static int
 254 str_adderr(char *str, int len, int err)
 255 {
 256     const char *msg;
 257     int  msglen;
 258
 259     msg = err == 0 ? "Not a number" : errmsg(err);
 260     msglen = strlen(msg) + 2;
 261     if (len <= msglen)
 262     {
 263         return(0);
 264     }
 265     (void) strcat(str, ": ");
 266     (void) strcat(str, msg);
 267     return(len - msglen);
 268 }
 269
 270 /*
 271  *  str_addarg(str, len, arg, first) - add the string argument "arg" to
 272  *      the string "str".  This is the first in the group when "first"
 273  *      is set (indicating that a comma should NOT be added to the front).
 274  */
 275 static int
 276 str_addarg(char *str, int len, char *arg, int first)
 277 {
 278     register int arglen;
 279
 280     arglen = strlen(arg);
 281     if (!first)
 282     {
 283         arglen += 2;
 284     }
 285     if (len <= arglen)
 286     {
 287         return(0);
 288     }
 289     if (!first)
 290     {
 291         (void) strcat(str, ", ");
 292     }
 293     (void) strcat(str, arg);
 294     return(len - arglen);
 295 }
 296
 297 /*
 298  *  err_compar(p1, p2) - comparison routine used by "qsort"
 299  *      for sorting errors.
 300  */
 301 static int
 302 err_compar(const void *arg1, const void *arg2)
 303 {
 304     const struct errs *p1 = arg1;
 305     const struct errs *p2 = arg2;
 306     int result;
 307
 308     if ((result = p1->errnum - p2->errnum) == 0)
 309     {
 310         return(strcmp(p1->arg, p2->arg));
 311     }
 312     return(result);
 313 }
 314
 315 /*
 316  *  error_count() - return the number of errors currently logged.
 317  */
 318
 319 int
 320 error_count(void)
 321 {
 322     return(errcnt);
 323 }
 324
 325 /*
 326  *  show_errors() - display on stdout the current log of errors.
 327  */
 328
 329 void
 330 show_errors(void)
 331 {
 332     register int cnt = 0;
 333     register struct errs *errp = errs;
 334
 335     printf("%d error%s:\n\n", errcnt, errcnt == 1 ? "" : "s");
 336     while (cnt++ < errcnt)
 337     {
 338         printf("%5s: %s\n", errp->arg,
 339             errp->errnum == 0 ? "Not a number" : errmsg(errp->errnum));
 340         errp++;
 341     }
 342 }
 343
 344 /*
 345  *  kill_procs(str) - send signals to processes, much like the "kill"
 346  *              command does; invoked in response to 'k'.
 347  */
 348
 349 const char *
 350 kill_procs(char *str)
 351 {
 352     register char *nptr;
 353     int signum = SIGTERM;       /* default */
 354     int procnum;
 355     struct sigdesc *sigp;
 356     int uid;
 357
 358     /* reset error array */
 359     ERR_RESET;
 360
 361     /* remember our uid */
 362     uid = getuid();
 363
 364     /* skip over leading white space */
 365     while (isspace(*str)) str++;
 366
 367     if (str[0] == '-')
 368     {
 369         /* explicit signal specified */
 370         if ((nptr = next_field(str)) == NULL)
 371         {
 372             return(" kill: no processes specified");
 373         }
 374
 375         if (isdigit(str[1]))
 376         {
 377             (void) scanint(str + 1, &signum);
 378             if (signum <= 0 || signum >= NSIG)
 379             {
 380                 return(" invalid signal number");
 381             }
 382         }
 383         else
 384         {
 385             /* translate the name into a number */
 386             for (sigp = sigdesc; sigp->name != NULL; sigp++)
 387             {
 388                 if (strcmp(sigp->name, str + 1) == 0)
 389                 {
 390                     signum = sigp->number;
 391                     break;
 392                 }
 393             }
 394
 395             /* was it ever found */
 396             if (sigp->name == NULL)
 397             {
 398                 return(" bad signal name");
 399             }
 400         }
 401         /* put the new pointer in place */
 402         str = nptr;
 403     }
 404
 405     /* loop thru the string, killing processes */
 406     do
 407     {
 408         if (scanint(str, &procnum) == -1)
 409         {
 410             ERROR(str, 0);
 411         }
 412         else
 413         {
 414             /* check process owner if we're not root */
 415             if (uid && (uid != proc_owner(procnum)))
 416             {
 417                 ERROR(str, EACCES);
 418             }
 419             /* go in for the kill */
 420             else if (kill(procnum, signum) == -1)
 421             {
 422                 /* chalk up an error */
 423                 ERROR(str, errno);
 424             }
 425         }
 426     } while ((str = next_field(str)) != NULL);
 427
 428     /* return appropriate error string */
 429     return(err_string());
 430 }
 431
 432 /*
 433  *  renice_procs(str) - change the "nice" of processes, much like the
 434  *              "renice" command does; invoked in response to 'r'.
 435  */
 436
 437 const char *
 438 renice_procs(char *str)
 439 {
 440     register char negate;
 441     int prio;
 442     int procnum;
 443     int uid;
 444
 445     ERR_RESET;
 446     uid = getuid();
 447
 448     /* allow for negative priority values */
 449     if ((negate = (*str == '-')) != 0)
 450     {
 451         /* move past the minus sign */
 452         str++;
 453     }
 454
 455     /* use procnum as a temporary holding place and get the number */
 456     procnum = scanint(str, &prio);
 457
 458     /* negate if necessary */
 459     if (negate)
 460     {
 461         prio = -prio;
 462     }
 463
 464 #if defined(PRIO_MIN) && defined(PRIO_MAX)
 465     /* check for validity */
 466     if (procnum == -1 || prio < PRIO_MIN || prio > PRIO_MAX)
 467     {
 468         return(" bad priority value");
 469     }
 470 #endif
 471
 472     /* move to the first process number */
 473     if ((str = next_field(str)) == NULL)
 474     {
 475         return(" no processes specified");
 476     }
 477
 478     /* loop thru the process numbers, renicing each one */
 479     do
 480     {
 481         if (scanint(str, &procnum) == -1)
 482         {
 483             ERROR(str, 0);
 484         }
 485
 486         /* check process owner if we're not root */
 487         else if (uid && (uid != proc_owner(procnum)))
 488         {
 489             ERROR(str, EACCES);
 490         }
 491         else if (setpriority(PRIO_PROCESS, procnum, prio) == -1)
 492         {
 493             ERROR(str, errno);
 494         }
 495     } while ((str = next_field(str)) != NULL);
 496
 497     /* return appropriate error string */
 498     return(err_string());
 499 }
 500