pkill/pgrep: support extended regular expressions

Done by enabling the REG_EXTENDED and REG_NOSUB regex flags,
which also increases compatibility with the procps versions.

Signed-off-by: Wade Berrier <wade_berrier@appsig.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/procps/pgrep.c b/procps/pgrep.c
index 156b4ad69..dc7ffff48 100644
--- a/procps/pgrep.c
+++ b/procps/pgrep.c
@@ -128,7 +128,7 @@ int pgrep_main(int argc UNUSED_PARAM, char **argv)
                 bb_show_usage();
 
         if (argv[0])
-                xregcomp(&re_buffer, argv[0], 0);
+                xregcomp(&re_buffer, argv[0], REG_EXTENDED | REG_NOSUB);
 
         matched_pid = 0;
         cmd_last = NULL;