diff options
Diffstat (limited to 'toys')
| -rw-r--r-- | toys/posix/ps.c | 67 |
1 files changed, 52 insertions, 15 deletions
diff --git a/toys/posix/ps.c b/toys/posix/ps.c index 76884c55..9b645aef 100644 --- a/toys/posix/ps.c +++ b/toys/posix/ps.c @@ -286,6 +286,8 @@ GLOBALS( void (*show_process)(void *tb); ) +/* Linked list of fields selected for display, in order, with :len and =title */ + struct strawberry { struct strawberry *next, *prev; short which, len, reverse; @@ -293,8 +295,15 @@ struct strawberry { char forever[]; }; -/* The slot[] array is mostly populated from /proc/$PID/stat (kernel proc.txt - * table 1-4) but we shift and repurpose fields, with the result being: */ +/* The function get_ps() reads all the data about one process, saving it in + * toybox as a struct carveup. Simple ps calls then pass toybuf directly to + * show_ps(), but features like sorting instead append a copy to a linked list + * for further processing once all processes have been read. + * + * struct carveup contains a slot[] array of 64 bit values, with the following + * data at each position in the array. Most is read from /proc/$PID/stat (see + * https://kernel.org/doc/Documentation/filesystems/proc.txt table 1-4) but + * we we replace several fields with don't use with other data. */ enum { SLOT_pid, /*process id*/ SLOT_ppid, // parent process id @@ -303,7 +312,7 @@ enum { 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_stime, /*kernel mode jiffies*/ SLOT_cutime, // utime+child utime 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 @@ -319,7 +328,7 @@ enum { 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_upticks, /*uptime-starttime*/ 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 @@ -328,24 +337,52 @@ enum { SLOT_tid, /*Thread ID*/ SLOT_tcount, // Thread count SLOT_pcy, /*Android sched policy*/ - SLOT_count + SLOT_count /* Size of array */ }; +/* In addition to slot[], carevup contains 6 string fields to display + command name, tty device, selinux label... They're stored one after the + other in str[] (separated by null terminators), and offset[] contains the + starting position of each string after the first (which is always 0). */ + // Data layout in toybuf struct carveup { long long slot[SLOT_count]; // data (see enum above) - unsigned short offset[6]; // offset of fields in str[] (skip name, always 0) + unsigned short offset[6]; // offset of fields in str[] (skip CMD, always 0) char state; - char str[]; // name, tty, command, wchan, attr, cmdline + char str[]; // CMD, TTY, WCHAN, LABEL, COMM, ARGS, NAME }; +/* The typos[] array lists all the types understood by "ps -o", I.E all the + * columns ps and top know how to display. Each entry has: + * + * name: the column name, displayed at top and used to select column with -o + * + * width: the display width. Fields are padded to this width when displaying + * to a terminal (negative means right justified). Strings are truncated + * to fit, numerical fields are padded but not truncated (although + * the display code reclaims unused padding from later fields to try to + * get the overflow back). + * + * slot: which slot[] out of carveup. Negative means it's a string field. + * Setting bit |64 requests extra display/sort processing. + * + * The TAGGED_ARRAY plumbing produces an enum of indexes, the "tag" is the + * first string argument and the prefix is the first argument to TAGGED_ARRAY + * so in this case "NAME" becomes PS_NAME which is the offset into typos[] + * for that entry, and also _PS_NAME (the bit position, 1<<PS_NAME). + * We record active columns in TT.bits, ala: + * + * if (TT.bits & _PS_NAME) printf("-o included PS_NAME"); + */ + // 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 + // Numbers. (What's in slot[] is what's displayed, sorted numerically.) {"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", 6, SLOT_rss}, {"PGID", 5, SLOT_pgrp}, @@ -354,31 +391,31 @@ struct typography { {"RTPRIO", 6, SLOT_rtprio}, {"SCH", 3, SLOT_policy}, {"CPU", 3, SLOT_taskcpu}, {"TID", 5, SLOT_tid}, {"TCNT", 4, SLOT_tcount}, {"BIT", 3, SLOT_bits}, - // String fields + // String fields (-1 is carveup->str, rest are str+offset[1-slot]) {"TTY", -8, -2}, {"WCHAN", -6, -3}, {"LABEL", -30, -4}, {"COMM", -27, -5}, {"NAME", -27, -7}, {"COMMAND", -27, -5}, {"CMDLINE", -27, -6}, {"ARGS", -27, -6}, {"CMD", -15, -1}, - // user/group + // user/group (may call getpwuid() or similar) {"UID", 5, SLOT_uid}, {"USER", -12, 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 + // clock displays (00:00:00) {"TIME", 8, SLOT_utime}, {"ELAPSED", 11, SLOT_starttime}, {"TIME+", 9, SLOT_utime}, - // Percentage displays + // Percentage displays (fixed point, one decimal digit. 123 -> 12.3) {"C", 1, SLOT_utime2}, {"%VSZ", 5, SLOT_vsize}, {"%MEM", 5, SLOT_rss}, {"%CPU", 4, SLOT_utime2}, - // human_readable + // human_readable (function human_readable() in lib, 1.23M, 1.4G, etc) {"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 + // Misc (special cases) {"STIME", 5, SLOT_starttime}, {"F", 1, 64|SLOT_flags}, {"S", -1, 64}, {"STAT", -5, 64}, {"PCY", 3, 64|SLOT_pcy}, ); @@ -1744,7 +1781,7 @@ void pgrep_main(void) TT.pgrep.self = getpid(); - // No signal names start with "L", so no need for "L: " parsing. + // No signal names start with "L", so no need for "L: " in optstr. if (TT.pgrep.L && 1>(TT.pgrep.signal = sig_to_num(TT.pgrep.L))) error_exit("bad -L '%s'", TT.pgrep.L); |