pgrep: fix "pgrep -v -P1"; also allow matching of comm - closes 10086

function                                             old     new   delta
pgrep_main                                           662     720     +58

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 37 insertions, 10 deletions

diff --git a/procps/pgrep.c b/procps/pgrep.c
index 327f6a934..a3ca9e295 100644
--- a/procps/pgrep.c
+++ b/procps/pgrep.c
@@ -155,15 +155,18 @@ int pgrep_main(int argc UNUSED_PARAM, char **argv)
         proc = NULL;
         while ((proc = procps_scan(proc, scan_mask)) != NULL) {
                 char *cmd;
-                int cmdlen;
+                int cmdlen, match;
 
                 if (proc->pid == pid)
                         continue;
 
-                if (ppid2match >= 0 && ppid2match != proc->ppid)
-                        continue;
-                if (sid2match >= 0 && sid2match != proc->sid)
-                        continue;
+                if (!OPT_INVERT) {
+                        /* Quickly reject -sN -PN mismatches... unless -v */
+                        if (ppid2match >= 0 && ppid2match != proc->ppid)
+                                continue;
+                        if (sid2match >= 0 && sid2match != proc->sid)
+                                continue;
+                }
 
                 cmdlen = -1;
                 cmd = proc->argv0;
@@ -186,12 +189,36 @@ int pgrep_main(int argc UNUSED_PARAM, char **argv)
                         }
                 }
 
+                if (OPT_INVERT) {
+                        /* "pgrep -v -P1 firefox" means "not (ppid=1 AND name=firefox)"
+                         * or equivalently "ppid!=1 OR name!=firefox".
+                         * Check the first condition and if true, skip matching.
+                         */
+                        if (ppid2match >= 0 && ppid2match != proc->ppid)
+                                goto got_it;
+                        if (sid2match >= 0 && sid2match != proc->sid)
+                                goto got_it;
+                }
+
+                match = !argv[0]; /* if no PATTERN, then it's a match, else... */
+                if (!match) {
+ again:
+                        match = (regexec(&re_buffer, cmd, 1, re_match, 0) == 0);
+                        if (!match && cmd != proc->comm) {
+                                /* if argv[] did not match, try comm */
+                                cmdlen = -1;
+                                cmd = proc->comm;
+                                goto again;
+                        }
+                        if (match && OPT_ANCHOR) {
+                                /* -x requires full string match */
+                                match = (re_match[0].rm_so == 0 && cmd[re_match[0].rm_eo] == '\0');
+                        }
+                }
+
                 /* NB: OPT_INVERT is always 0 or 1 */
-                if (!argv[0]
-                 || (regexec(&re_buffer, cmd, 1, re_match, 0) == 0 /* match found */
-                    && (!OPT_ANCHOR || (re_match[0].rm_so == 0 && re_match[0].rm_eo == (regoff_t)strlen(cmd)))
-                    ) ^ OPT_INVERT
-                ) {
+                if (match ^ OPT_INVERT) {
+ got_it:
                         matched_pid = proc->pid;
                         if (OPT_LAST) {
                                 free(cmd_last);