1 /* ps.c - show process list
2 *
3 * Copyright 2015 Rob Landley <rob@landley.net>
4 *
5 * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ps.html
6 * And http://kernel.org/doc/Documentation/filesystems/proc.txt Table 1-4
7 * And linux kernel source fs/proc/array.c function do_task_stat()
8 *
9 * Deviations from posix: no -n to specify an alternate /etc/passwd (??!?)
10 * Posix says default output should have field named "TTY" but if you "-o tty"
11 * the same field should be called "TT" which is _INSANE_ and I'm not doing it.
12 * It also says that -o "args" and "comm" should behave differently but use
13 * the same title, which is not the same title as the default output. No.
14
15 USE_PS(NEWTOY(ps, "aAdeflo*[!ol][+Ae]", TOYFLAG_USR|TOYFLAG_BIN))
16
17 config PS
18 bool "ps"
19 default n
20 help
21 usage: ps [-Aade] [-fl] [-gG GROUP] [-o FIELD] [-p PID] [-t TTY] [-u USER]
22
23 List processes.
24
25 -A All processes
26 -a Processes with terminals, except session leaders
27 -d Processes that aren't session leaders
28 -e Same as -A
29 -f Full listing
30 -l Long listing
31
32 -g Processes belonging to these session leaders
33 -G Processes with these real group IDs
34 -o Show FIELDS for each process
35 -p select by PID
36 -t select by TTY
37 -u select by USER
38 -U select by USER
39
40 GROUP, FIELD, PID, TTY, and USER are comma separated lists.
41
42 OUTPUT (-o) FIELDS:
43
44 "UID", "PID", "PPID", "C", "PRI", "NI", "ADDR", "SZ",
45 "WCHAN", "STIME", "TTY", "TIME", "CMD", "COMMAND", "ELAPSED", "GROUP",
46 "%CPU", "PGID", "RGROUP", "RUSER", "USER", "VSZ"
47
48 C Processor utilization for scheduling
49 F Process flags (PF_*) from linux source file include/sched.h
50 (in octal rather than hex because posix)
51 S Process state:
52 R (running) S (sleeping) D (disk sleep) T (stopped) t (tracing stop)
53 Z (zombie) X (dead) x (dead) K (wakekill) W (waking)
54 PID Process id
55 PPID Parent process id
56 PRI Priority
57 UID User id of process owner
58
59 Default output is -o PID,TTY,TIME,CMD
60 With -f USER=UID,PID,PPID,C,STIME,TTY,TIME,CMD
61 With -l F,S,UID,PID,PPID,C,PRI,NI,ADDR,SZ,WCHAN,TTY,TIME,CMD
62 */
63
64 #define FOR_ps
65 #include "toys.h"
66
67 GLOBALS(
68 struct arg_list *o;
69
70 unsigned width;
71 dev_t tty;
72 void *fields;
73 long uptime;
74 )
75
76 /*
77 l l fl a fl fl l l l l l f a a a
78 F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD
79 ruser user rgroup group pid ppid pgid pcpu vsz nice etime time tty comm args
80
81 todo: thread support /proc/$d/task/%d/stat
82 man page: F flags mean...
83 */
84
85 struct strawberry {
86 struct strawberry *next, *prev;
87 short which, len;
88 char title[];
89 };
90
91 // dirtree callback.
92 // toybuf used as: 1024 /proc/$PID/stat, 1024 slot[], 2048 /proc/$PID/cmdline
do_ps(struct dirtree * new)93 static int do_ps(struct dirtree *new)
94 {
95 struct strawberry *field;
96 long long *slot = (void *)(toybuf+1024);
97 char *name, *s, state;
98 int nlen, i, fd, len, width = TT.width;
99
100 if (!new->parent) return DIRTREE_RECURSE;
101 if (!(*slot = atol(new->name))) return 0;
102
103 // name field limited to 256 bytes by VFS, plus 40 fields * max 20 chars:
104 // 1000-ish total, but some forced zero so actually there's headroom.
105 sprintf(toybuf, "%lld/stat", *slot);
106 if (!readfileat(dirtree_parentfd(new), toybuf, toybuf, 1024)) return 0;
107
108 // parse oddball fields (name and state)
109 if (!(s = strchr(toybuf, '('))) return 0;
110 for (name = ++s; *s != ')'; s++) if (!*s) return 0;
111 nlen = s++-name;
112 if (1>sscanf(++s, " %c%n", &state, &i)) return 0;
113
114 // parse numeric fields
115 for (len = 1; len<100; len++)
116 if (1>sscanf(s += i, " %lld%n", slot+len, &i)) break;
117
118 // skip entries we don't care about.
119 if ((toys.optflags&(FLAG_a|FLAG_d)) && getsid(*slot)==*slot) return 0;
120 if ((toys.optflags&FLAG_a) && !slot[4]) return 0;
121 if (!(toys.optflags&(FLAG_a|FLAG_d|FLAG_A|FLAG_e)) && TT.tty!=slot[4])
122 return 0;
123
124 for (field = TT.fields; field; field = field->next) {
125 char *out = toybuf+2048;
126
127 // Default: unsupported (5 "C")
128 sprintf(out, "-");
129
130 // PID, PPID, PRI, NI, ADDR, SZ
131 if (-1 != (i = stridx((char[]){3,4,6,7,8,9,0}, field->which)))
132 sprintf(out, ((1<<i)&0x10) ? "%llx" : "%lld",
133 slot[((char[]){0,2,16,17,22})[i]]>>(((1<<i)&0x20) ? 12 : 0));
134 // F
135 else if (!(i = field->which)) sprintf(out, "%llo", slot[7]);
136 // S
137 else if (i == 1)
138 sprintf(out, "%c", state);
139 // UID and USER
140 else if (i == 2 || i == 22) {
141 sprintf(out, "%d", new->st.st_uid);
142 if (i == 22) {
143 struct passwd *pw = getpwuid(new->st.st_uid);
144
145 if (pw) out = pw->pw_name;
146 }
147 // WCHAN
148 } else if (i==10) {
149 sprintf(toybuf+512, "%lld/wchan", *slot);
150 readfileat(dirtree_parentfd(new), toybuf+512, out, 2047);
151
152 // STIME
153 // TTY
154 } else if (i==12) {
155
156 // Can we readlink() our way to a name?
157 for (i=0; i<3; i++) {
158 struct stat st;
159
160 sprintf(toybuf+512, "%lld/fd/%i", *slot, i);
161 fd = dirtree_parentfd(new);
162 if (!fstatat(fd, toybuf+512, &st, 0) && S_ISCHR(st.st_mode)
163 && st.st_rdev == slot[4]
164 && 0<(len = readlinkat(fd, toybuf+512, out, 2047)))
165 {
166 out[len] = 0;
167 if (!strncmp(out, "/dev/", 5)) out += 5;
168
169 break;
170 }
171 }
172
173 // Couldn't find it, show major:minor
174 if (i==3) {
175 i = slot[4];
176 sprintf(out, "%d:%d", (i>>8)&0xfff, ((i>>12)&0xfff00)|(i&0xff));
177 }
178
179 // TIME ELAPSED
180 } else if (i==13 || i==16) {
181 long seconds = (i==16) ? slot[20] : slot[11]+slot[12], ll = 60*60*24;
182
183 seconds /= sysconf(_SC_CLK_TCK);
184 if (i==16) seconds = TT.uptime-seconds;
185 for (s = out, i = 0; i<4; i++) {
186 if (i>1 || seconds > ll)
187 s += sprintf(s, (i==3) ? "%02ld" : "%ld%c", seconds/ll, "-::"[i]);
188 seconds %= ll;
189 ll /= i ? 60 : 24;
190 }
191
192 //16 "ELAPSED", "GROUP", "%CPU", "PGID", "RGROUP",
193 //21 "RUSER", -, "VSZ"
194
195 // Command line limited to 2k displayable. We could dynamically malloc, but
196 // it'd almost never get used, querying length of a proc file is awkward,
197 // fixed buffer is nommu friendly... Wait for somebody to complain. :)
198 } else if (i == 14 || i == 15) {
199 int fd;
200
201 len = 0;
202 sprintf(out, "%lld/cmdline", *slot);
203 fd = openat(dirtree_parentfd(new), out, O_RDONLY);
204
205 if (fd != -1) {
206 if (0<(len = read(fd, out, 2047))) {
207 if (!out[len-1]) len--;
208 else out[len] = 0;
209 for (i = 0; i<len; i++) if (out[i] < ' ') out[i] = ' ';
210 }
211 close(fd);
212 }
213 if (len<1) sprintf(out, "[%.*s]", nlen, name);
214 }
215
216 i = width<field->len ? width : field->len;
217 width -= printf(" %*.*s", i, field->next ? i : width, out);
218 }
219 xputc('\n');
220
221 return 0;
222 }
223
ps_main(void)224 void ps_main(void)
225 {
226 struct strawberry *field;
227 // Octal output code followed by header name
228 char widths[] = {1,1,5,5,5,2,3,3,4,5,6,5,8,8,27,27,11,8,4,5,8,8,8,6},
229 *typos[] = {
230 "F", "S", "UID", "PID", "PPID", "C", "PRI", "NI", "ADDR", "SZ",
231 "WCHAN", "STIME", "TTY", "TIME", "CMD", "COMMAND", "ELAPSED", "GROUP",
232 "%CPU", "PGID", "RGROUP", "RUSER", "USER", "VSZ"
233 };
234 int i, fd = -1;
235
236 TT.width = 80;
237 terminal_size(&TT.width, 0);
238 TT.width--;
239
240 // find controlling tty, falling back to /dev/tty if none
241 for (i = fd = 0; i < 4; i++) {
242 struct stat st;
243
244 if (i != 3 || -1 != (i = fd = open("/dev/tty", O_RDONLY))) {
245 if (isatty(i) && !fstat(i, &st)) {
246 TT.tty = st.st_rdev;
247 break;
248 }
249 }
250 }
251 if (fd != -1) close(fd);
252
253 sysinfo((void *)toybuf);
254 // Because "TT.uptime = *(long *)toybuf;" triggers a bug in gcc.
255 {
256 long *sigh = (long *)toybuf;
257 TT.uptime = *sigh;
258 }
259
260 // Manual field selection via -o
261 if (toys.optflags&FLAG_o) {
262 struct arg_list *ol;
263 int length;
264
265 for (ol = TT.o; ol; ol = ol->next) {
266 char *width, *type, *title, *end, *arg = ol->arg;
267
268 // Set title, length of title, type, end of type, and display width
269 while ((type = comma_iterate(&arg, &length))) {
270 if ((end = strchr(type, '=')) && length<(end-type)) {
271 title = end+1;
272 length = (end-type)-1;
273 } else {
274 end = type+length;
275 title = 0;
276 }
277
278 // If changing display width, trim title at the :
279 if ((width = strchr(type, ':')) && width<end) {
280 if (!title) length = width-type;
281 } else width = 0;
282
283 // Allocate structure, copy title
284 field = xmalloc(sizeof(struct strawberry)+length+1);
285 if (title) {
286 memcpy(field->title, title, length);
287 field->title[length] = 0;
288 }
289 field->len = length;
290
291 if (width) {
292 field->len = strtol(++width, &title, 10);
293 if (!isdigit(*width) || title != end)
294 error_exit("bad : in -o %s@%ld", ol->arg, title-ol->arg);
295 end = width;
296 }
297
298 // Find type (reuse width as temp because we're done with it)
299 for (i = 0; i<ARRAY_LEN(typos) && !field->which; i++) {
300 int j, k;
301 char *s;
302
303 field->which = i;
304 for (j = 0; j < 2; j++) {
305 if (!j) s = typos[i];
306 // posix requires alternate names for some fields
307 else if (-1 == (k = stridx((char []){7, 14, 15, 16}, i))) break;
308 else s = ((char *[]){"nice", "args", "comm", "etime"})[k];
309
310 if (!strncasecmp(type, s, end-type) && strlen(s)==end-type) break;
311 }
312 if (j!=2) break;
313 }
314 if (i == ARRAY_LEN(typos)) error_exit("bad -o %.*s", end-type, type);
315 if (!field->title) strcpy(field->title, typos[field->which]);
316 dlist_add_nomalloc((void *)&TT.fields, (void *)field);
317 }
318 }
319
320 // Default fields (also with -f and -l)
321 } else {
322 unsigned short def = 0x7008;
323
324 if (toys.optflags&FLAG_f) def = 0x783c;
325 if (toys.optflags&FLAG_l) def = 0x77ff;
326
327 // order of fields[] matches posix STDOUT section, so add enabled XSI
328 // defaults according to bitmask
329
330 for (i=0; def>>i; i++) {
331 if (!((def>>i)&1)) continue;
332
333 field = xmalloc(sizeof(struct strawberry)+strlen(typos[i])+1);
334 field->which = i;
335 field->len = widths[i];
336 strcpy(field->title, typos[i]);
337 dlist_add_nomalloc((void *)&TT.fields, (void *)field);
338 }
339 }
340 dlist_terminate(TT.fields);
341
342 // Print padded headers. (Numbers are right justified, everyting else left.
343 // time and pcpu count as numbers, tty does not)
344 for (field = TT.fields; field; field = field->next) {
345
346 // right justify F, UID, PID, PPID, PRI, NI, ADDR SZ, TIME, ELAPSED, %CPU
347 // todo: STIME? C?
348 if (!((1<<field->which)&0x523dd)) field->len *= -1;
349 printf(" %*s", field->len, field->title);
350
351 // -f prints USER but calls it UID (but "ps -o uid -f" is numeric...?)
352 if ((toys.optflags&(FLAG_f|FLAG_o))==FLAG_f && field->which==2)
353 field->which = 22;
354 }
355 xputc('\n');
356
357 dirtree_read("/proc", do_ps);
358 }
359