From e751606fccdeed7ab79fc4324938b3aa47989842 Mon Sep 17 00:00:00 2001 From: Jaromir Capik Date: Thu, 10 Jul 2014 21:14:02 +0200 Subject: [PATCH] ps: add -q/q/--quick-pid option This commit introduces a new option q/-q/--quick-pid to the 'ps' command. The option does a similar job to the p/-p/--pid option (i.e. selection of PIDs listed in the comma separated list that follows the option), but the new option is optimized for speed. In cases where users only need to specify a list of PIDs to be shown and don't need other selection options, forest type output and sorting options, the new option is recommended as it decreases the initial processing delay by avoiding reading the necessary information from all the processes running on the system and by simplifying the internal filtering logic. --- ps/common.h | 1 + ps/display.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++- ps/help.c | 6 +++-- ps/parser.c | 25 ++++++++++++++++++ ps/ps.1 | 27 ++++++++++++++++++- ps/select.c | 1 + 6 files changed, 131 insertions(+), 4 deletions(-) diff --git a/ps/common.h b/ps/common.h index 157e6dfb..16654d2f 100644 --- a/ps/common.h +++ b/ps/common.h @@ -41,6 +41,7 @@ #define SEL_SESS 12 #define SEL_COMM 13 #define SEL_PPID 14 +#define SEL_PID_QUICK 15 /* Since an enum could be smashed by a #define, it would be bad. */ #define U98 0 /* Unix98 standard */ /* This must be 0 */ diff --git a/ps/display.c b/ps/display.c index 693154bd..a8d952ad 100644 --- a/ps/display.c +++ b/ps/display.c @@ -164,6 +164,7 @@ static void arg_show(void){ case SEL_FGID: show_gid("FGID", walk->n, walk->u); break; case SEL_PGRP: show_pid("PGRP", walk->n, walk->u); break; case SEL_PID : show_pid("PID ", walk->n, walk->u); break; + case SEL_PID_QUICK : show_pid("PID_QUICK ", walk->n, walk->u); break; case SEL_PPID: show_pid("PPID", walk->n, walk->u); break; case SEL_TTY : show_tty("TTY ", walk->n, walk->u); break; case SEL_SESS: show_pid("SESS", walk->n, walk->u); break; @@ -343,8 +344,29 @@ static int want_this_proc_pcpu(proc_t *buf){ static void simple_spew(void){ static proc_t buf, buf2; // static avoids memset PROCTAB* ptp; + pid_t* pidlist; + int flags; + int i; - ptp = openproc(needs_for_format | needs_for_sort | needs_for_select | needs_for_threads); + pidlist = NULL; + flags = needs_for_format | needs_for_sort | needs_for_select | needs_for_threads; + + // -q option (only single SEL_PID_QUICK typecode entry expected in the list, if present) + if (selection_list && selection_list->typecode == SEL_PID_QUICK) { + flags |= PROC_PID; + + pidlist = (pid_t*) malloc(selection_list->n * sizeof(pid_t)); + if (!pidlist) { + fprintf(stderr, _("error: not enough memory\n")); + exit(1); + } + + for (i = 0; i < selection_list->n; i++) { + pidlist[i] = selection_list->u[selection_list->n-i-1].pid; + } + } + + ptp = openproc(flags, pidlist); if(!ptp) { fprintf(stderr, _("error: can not access /proc\n")); exit(1); @@ -385,6 +407,8 @@ static void simple_spew(void){ break; } closeproc(ptp); + + if (pidlist) free(pidlist); } /***** forest output requires sorting by ppid; add start_time by default */ @@ -539,6 +563,52 @@ static void fancy_spew(void){ closeproc(ptp); } +static void arg_check_conflicts(void) +{ + int selection_list_len; + int has_quick_pid; + + selection_node *walk = selection_list; + has_quick_pid = 0; + selection_list_len = 0; + + while (walk) { + if (walk->typecode == SEL_PID_QUICK) has_quick_pid++; + walk = walk->next; + selection_list_len++; + } + + /* -q doesn't allow multiple occurences */ + if (has_quick_pid > 1) { + fprintf(stderr, "q/-q/--quick-pid can only be used once.\n"); + exit(1); + } + + /* -q doesn't allow combinations with other selection switches */ + if (has_quick_pid && selection_list_len > has_quick_pid) { + fprintf(stderr, "q/-q/--quick-pid cannot be combined with other selection options.\n"); + exit(1); + } + + /* -q cannot be used with forest type listings */ + if (has_quick_pid && forest_type) { + fprintf(stderr, "q/-q/--quick-pid cannot be used together with forest type listings.\n"); + exit(1); + } + + /* -q cannot be used with sort */ + if (has_quick_pid && sort_list) { + fprintf(stderr, "q/-q,--quick-pid cannot be used together with sort options.\n"); + exit(1); + } + + /* -q cannot be used with -N */ + if (has_quick_pid && negate_selection) { + fprintf(stderr, "q/-q/--quick-pid cannot be used together with negation switches.\n"); + exit(1); + } + +} /***** no comment */ int main(int argc, char *argv[]){ @@ -580,6 +650,9 @@ int main(int argc, char *argv[]){ reset_global(); /* must be before parser */ arg_parse(argc,argv); + /* check for invalid combination of arguments */ + arg_check_conflicts(); + /* arg_show(); */ trace("screen is %ux%u\n",screen_cols,screen_rows); /* printf("sizeof(proc_t) is %d.\n", sizeof(proc_t)); */ diff --git a/ps/help.c b/ps/help.c index 8bde12b8..4c3e9966 100644 --- a/ps/help.c +++ b/ps/help.c @@ -111,8 +111,10 @@ void do_help (const char *opt, int rc) { fputs(_(" -C command name\n"), out); fputs(_(" -G, --Group real group id or name\n"), out); fputs(_(" -g, --group session or effective group name\n"), out); - fputs(_(" -p, --pid process id\n"), out); - fputs(_(" --ppid select by parent process id\n"), out); + fputs(_(" -p, p, --pid process id\n"), out); + fputs(_(" --ppid parent process id\n"), out); + fputs(_(" -q, q, --quick-pid \n" + " process id (quick mode)\n"), out); fputs(_(" -s, --sid session id\n"), out); fputs(_(" -t, t, --tty terminal\n"), out); fputs(_(" -u, U, --user effective user id or name\n"), out); diff --git a/ps/parser.c b/ps/parser.c index 6e6df517..ad49459f 100644 --- a/ps/parser.c +++ b/ps/parser.c @@ -426,6 +426,14 @@ static const char *parse_sysv_option(void){ if(err) return err; selection_list->typecode = SEL_PID; return NULL; /* can't have any more options */ + case 'q': /* end */ + trace("-q quick select by PID.\n"); + arg=get_opt_arg(); + if(!arg) return "List of process IDs must follow -q."; + err=parse_list(arg, parse_pid); + if(err) return err; + selection_list->typecode = SEL_PID_QUICK; + return NULL; /* can't have any more options */ #if 0 case 'r': trace("-r some Digital Unix thing about warnings...\n"); @@ -696,6 +704,14 @@ static const char *parse_bsd_option(void){ if(err) return err; selection_list->typecode = SEL_PID; return NULL; /* can't have any more options */ + case 'q': /* end */ + trace("q Quick select by process ID\n"); + arg=get_opt_arg(); + if(!arg) return "List of process IDs must follow q."; + err=parse_list(arg, parse_pid); + if(err) return err; + selection_list->typecode = SEL_PID_QUICK; + return NULL; /* can't have any more options */ case 'r': trace("r select running processes\n"); running_only = 1; @@ -820,6 +836,7 @@ static const char *parse_gnu_option(void){ {"noheadings", &&case_noheadings}, {"pid", &&case_pid}, {"ppid", &&case_ppid}, + {"quick-pid", &&case_pid_quick}, {"rows", &&case_rows}, {"sid", &&case_sid}, {"sort", &&case_sort}, @@ -949,6 +966,14 @@ static const char *parse_gnu_option(void){ if(err) return err; selection_list->typecode = SEL_PID; return NULL; + case_pid_quick: + trace("--quick-pid\n"); + arg = grab_gnu_arg(); + if(!arg) return "List of process IDs must follow --quick-pid."; + err=parse_list(arg, parse_pid); + if(err) return err; + selection_list->typecode = SEL_PID_QUICK; + return NULL; case_ppid: trace("--ppid\n"); arg = grab_gnu_arg(); diff --git a/ps/ps.1 b/ps/ps.1 index b24fa1c8..ad4c78b2 100644 --- a/ps/ps.1 +++ b/ps/ps.1 @@ -143,7 +143,7 @@ Print only the process IDs of syslogd: .B ps\ \-C\ syslogd\ \-o\ pid= .TP Print only the name of PID 42: -.B ps\ \-p\ 42\ \-o\ comm= +.B ps\ \-q\ 42\ \-o\ comm= .PP .PP .\" """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" @@ -305,6 +305,31 @@ process\ ID in That is, it selects processes that are children of those listed in .IR pidlist . .TP +.BI q \ pidlist +Select by process ID (quick mode). Identical to +.B \-q +and +.BR \-\-quick\-pid . +.TP +.BI \-q \ pidlist +Select by PID (quick mode). This selects the processes whose process ID numbers appear in +.IR pidlist . +With this option \fBps\fR reads the necessary info only +for the pids listed in the \fIpidlist\fR and doesn't apply +additional filtering rules. The order of pids is unsorted +and preserved. No additional selection options, sorting +and forest type listings are allowed in this mode. +Identical to +.B q +and +.BR \-\-quick\-pid . +.TP +.BI \-\-quick\-pid \ pidlist +Select by process\ ID (quick mode). Identical to +.B \-q +and +.BR q . +.TP .BI \-s \ sesslist Select by session ID. This selects the processes with a session ID specified in diff --git a/ps/select.c b/ps/select.c index 619d8954..e12982d1 100644 --- a/ps/select.c +++ b/ps/select.c @@ -111,6 +111,7 @@ static int proc_was_listed(proc_t *buf){ break; case SEL_PGRP: return_if_match(pgrp,pid); break; case SEL_PID : return_if_match(tgid,pid); + break; case SEL_PID_QUICK : return_if_match(tgid,pid); break; case SEL_PPID: return_if_match(ppid,ppid); break; case SEL_TTY : return_if_match(tty,tty); break; case SEL_SESS: return_if_match(session,pid);