I'm having issue with the following code, not sure how else I can write it
(defun padname (strg)
(string-match "[uU]_\\(.*\\)\\(_[0-9\]+\\)?" strg)
(match-string 1 strg)
)
(padname "u_CLR_REQ_SUP_00")
"CLR_REQ_SUP_00" ==> expect "CLR_REQ_SUP"
(padname "u_CLR_REQ_SUP_0")
"CLR_REQ_SUP_0" ==> expect "CLR_REQ_SUP"
(padname "u_PTO_AVDD_3P3_0")
"PTO_AVDD_3P3_0" ==> expect "PTO_AVDD_3P3"
(padname "u_PTO_0")
"PTO_0" ==> expect "PTO"
(padname "u_PTO")
"PTO" ==> as expected
(padname "u_BTNI")
"BTNI" ==> as expected
Another variation, use greedy dot with [^0-9_][0-9]* at the end to stop at last non-digit with any digits after and combine with the optional group:
[Uu]_\\(.*[^0-9_][0-9]*\\)\\(_[0-9]+\\)?$
See regex proof.
EXPLANATION
--------------------------------------------------------------------------------
[Uu] any character of: 'U', 'u'
--------------------------------------------------------------------------------
_ '_'
--------------------------------------------------------------------------------
( group and capture to \1:
--------------------------------------------------------------------------------
.* any character except \n (0 or more times
(matching the most amount possible))
--------------------------------------------------------------------------------
[^0-9_] any character except: '0' to '9', '_'
--------------------------------------------------------------------------------
[0-9]* any character of: '0' to '9' (0 or more
times (matching the most amount
possible))
--------------------------------------------------------------------------------
) end of \1
--------------------------------------------------------------------------------
( group and capture to \2 (optional
(matching the most amount possible)):
--------------------------------------------------------------------------------
_ '_'
--------------------------------------------------------------------------------
[0-9]+ any character of: '0' to '9' (1 or more
times (matching the most amount
possible))
--------------------------------------------------------------------------------
)? end of \2 (NOTE: because you are using a
quantifier on this capture, only the LAST
repetition of the captured pattern will be
stored in \2)
--------------------------------------------------------------------------------
$ before an optional \n, and the end of the
string