hashcat pipe to solve words get rejected

[freeroute]

According to this thread https://hashcat.net/forum/thread-5744-po...l#pid30925
I tried 2 methods.The 1st didn't work for me. I would like to know why. Have you any idea?
Rule file created according to this thread: https://hashcat.net/forum/thread-5768-po...l#pid30938

1st' method command (with or without -w 3): hashcat /usr/share/wordlists/Surnames.dic -r /usr/share/hashcat/rules/toggle_first_and_append_digits.rule | hashcat -D 1 --force -m 2500 31540_1470931350.hccap

Starting attack in stdin mode...         

ERROR: No hashes loaded                 
                                                          
Session.Name...: hashcat
Status.........: Exhausted
Input.Mode.....: Pipe
Hash.Target....: 9FAD2F (00:1f:fb:9f:ad:2c <-> cc:07:e4:d7:8b:dc)
Hash.Type......: WPA/WPA2
Time.Started...: Sun Aug 21 12:57:12 2016 (6 secs)
Speed.Dev.#1...:        0 H/s (0.17ms)
Recovered......: 0/1 (0.00%) Digests, 0/1 (0.00%) Salts
Progress.......: 3
Rejected.......: 1

Started: Sun Aug 21 12:57:12 2016
Stopped: Sun Aug 21 12:57:19 2016

and hashcat exit.

2nd method working:
Command: hashcat -D 1 --force -m 2500 -a 0 31540_1470931350.hccap /usr/share/wordlists/Surnames.dic -j ^X^X^X^X^X -r pre.rule -r /usr/share/hashcat/rules/toggle_first_and_append_digits.rule

Session.Name...: hashcat
Status.........: Aborted
Rules.Type.....: File (pre.rule), File (/usr/share/hashcat/rules/toggle_first_and_append_digits.rule)
Input.Mode.....: File (/usr/share/wordlists/Surnames.dic)
Hash.Target....: 9FAD2F (00:1f:fb:9f:ad:2c <-> cc:07:e4:d7:8b:dc)
Hash.Type......: WPA/WPA2
Time.Started...: Sun Aug 21 12:58:22 2016 (3 secs)
Time.Estimated.: Wed Aug 24 03:33:27 2016 (2 days, 14 hours)
Speed.Dev.#1...:      780 H/s (12.64ms)
Recovered......: 0/1 (0.00%) Digests, 0/1 (0.00%) Salts
Progress.......: 2532/175733200 (0.00%)
Rejected.......: 100/2532 (3.95%)
Restore.Point..: 0/1757332 (0.00%)

Started: Sun Aug 21 12:58:22 2016
Stopped: Sun Aug 21 12:58:28 2016

Thanks for your reply.

[philsmd]

If you do not want hashcat to crack the hashes but output the password candidates to stdout, you of course shouldn't forget the flag within the first command of the pipe:
--stdout