Yep, I checked:
[postgres@uxmal standby_node]$ /bin/tar -xzf /db/wal_archives/00000001000001ED000000FB.tar.gz -C /db/standby_node/pg_xlog/
[postgres@uxmal standby_node]$ echo $?
0
[postgres@uxmal standby_node]$ ls /db/standby_node/pg_xlog/ | grep 00000001000001ED000000FB
00000001000001ED000000FB
I read somewhere that in order for the extracted file to be placed at a custom location you had to use that option -C
I'll try rewriting the command and debug it. Thanks for your comment.