# "else", and "fi" in if-then-else likewise must not end with "&&", thus
# receives similar treatment.
#
+# Swallowing here-docs with arbitrary tags requires a bit of finesse. When a
+# line such as "cat <<EOF >out" is seen, the here-doc tag is moved to the front
+# of the line enclosed in angle brackets as a sentinel, giving "<EOF>cat >out".
+# As each subsequent line is read, it is appended to the target line and a
+# (whitespace-loose) back-reference match /^<(.*)>\n\1$/ is attempted to see if
+# the content inside "<...>" matches the entirety of the newly-read line. For
+# instance, if the next line read is "some data", when concatenated with the
+# target line, it becomes "<EOF>cat >out\nsome data", and a match is attempted
+# to see if "EOF" matches "some data". Since it doesn't, the next line is
+# attempted. When a line consisting of only "EOF" (and possible whitespace) is
+# encountered, it is appended to the target line giving "<EOF>cat >out\nEOF",
+# in which case the "EOF" inside "<...>" does match the text following the
+# newline, thus the closing here-doc tag has been found. The closing tag line
+# and the "<...>" prefix on the target line are then discarded, leaving just
+# the target line "cat >out".
+#
# To facilitate regression testing (and manual debugging), a ">" annotation is
# applied to the line containing ")" which closes a subshell, ">>" to a line
# closing a nested subshell, and ">>>" to a line closing both at once. This
# here-doc -- swallow it to avoid false hits within its body (but keep the
# command to which it was attached)
-/<<[ ]*[-\\]*EOF[ ]*/ {
- s/[ ]*<<[ ]*[-\\]*EOF//
- h
- :hereslurp
+/<<[ ]*[-\\'"]*[A-Za-z0-9_]/ {
+ s/^\(.*\)<<[ ]*[-\\'"]*\([A-Za-z0-9_][A-Za-z0-9_]*\)['"]*/<\2>\1<</
+ s/[ ]*<<//
+ :hered
N
- s/.*\n//
- /^[ ]*EOF[ ]*$/!bhereslurp
- x
+ /^<\([^>]*\)>.*\n[ ]*\1[ ]*$/!{
+ s/\n.*$//
+ bhered
+ }
+ s/^<[^>]*>//
+ s/\n.*$//
}
# one-liner "(...) &&"
b
:subshell
-# bare "(" line?
+# bare "(" line? -- stash for later printing
/^[ ]*([ ]*$/ {
- # stash for later printing
h
bnextline
}
:slurp
# incomplete line "...\"
-/\\$/bincomplete
-# multi-line quoted string "...\n..."
-/^[^"]*"[^"]*$/bdqstring
-# multi-line quoted string '...\n...' (but not contraction in string "it's so")
-/^[^']*'[^']*$/{
+/\\$/bicmplte
+# multi-line quoted string "...\n..."?
+/"/bdqstring
+# multi-line quoted string '...\n...'? (but not contraction in string "it's")
+/'/{
/"[^'"]*'[^'"]*"/!bsqstring
}
+:folded
# here-doc -- swallow it
-/<<[ ]*[-\\]*EOF/bheredoc
-/<<[ ]*[-\\]*EOT/bheredoc
-/<<[ ]*[-\\]*INPUT_END/bheredoc
+/<<[ ]*[-\\'"]*[A-Za-z0-9_]/bheredoc
# comment or empty line -- discard since final non-comment, non-empty line
# before closing ")", "done", "elsif", "else", or "fi" will need to be
# re-visited to drop "suspect" marking since final line of those constructs
/"[^"]*#[^"]*"/!s/[ ]#.*$//
}
# one-liner "case ... esac"
-/^[ ]*case[ ]*..*esac/bcheckchain
+/^[ ]*case[ ]*..*esac/bchkchn
# multi-line "case ... esac"
/^[ ]*case[ ]..*[ ]in/bcase
# multi-line "for ... done" or "while ... done"
/^[ ]*fi[ ]*[<>|]/bdone
/^[ ]*fi[ ]*)/bdone
# nested one-liner "(...) &&"
-/^[ ]*(.*)[ ]*&&[ ]*$/bcheckchain
+/^[ ]*(.*)[ ]*&&[ ]*$/bchkchn
# nested one-liner "(...)"
-/^[ ]*(.*)[ ]*$/bcheckchain
+/^[ ]*(.*)[ ]*$/bchkchn
# nested one-liner "(...) >x" (or "2>x" or "<x" or "|x")
-/^[ ]*(.*)[ ]*[0-9]*[<>|]/bcheckchain
+/^[ ]*(.*)[ ]*[0-9]*[<>|]/bchkchn
# nested multi-line "(...\n...)"
/^[ ]*(/bnest
# multi-line "{...\n...}"
/^[ ]*{/bblock
# closing ")" on own line -- exit subshell
-/^[ ]*)/bclosesolo
+/^[ ]*)/bclssolo
# "$((...))" -- arithmetic expansion; not closing ")"
-/\$(([^)][^)]*))[^)]*$/bcheckchain
+/\$(([^)][^)]*))[^)]*$/bchkchn
# "$(...)" -- command substitution; not closing ")"
-/\$([^)][^)]*)[^)]*$/bcheckchain
+/\$([^)][^)]*)[^)]*$/bchkchn
# multi-line "$(...\n...)" -- command substitution; treat as nested subshell
-/\$([ ]*$/bnest
+/\$([^)]*$/bnest
# "=(...)" -- Bash array assignment; not closing ")"
-/=(/bcheckchain
+/=(/bchkchn
# closing "...) &&"
/)[ ]*&&[ ]*$/bclose
# closing "...)"
/)[ ]*$/bclose
# closing "...) >x" (or "2>x" or "<x" or "|x")
/)[ ]*[<>|]/bclose
-:checkchain
+:chkchn
# mark suspect if line uses ";" internally rather than "&&" (but not ";" in a
# string and not ";;" in one-liner "case...esac")
/;/{
bslurp
# found incomplete line "...\" -- slurp up next line
-:incomplete
+:icmplte
N
s/\\\n//
bslurp
-# found multi-line double-quoted string "...\n..." -- slurp until end of string
+# check for multi-line double-quoted string "...\n..." -- fold to one line
:dqstring
-s/"//g
+# remove all quote pairs
+s/"\([^"]*\)"/@!\1@!/g
+# done if no dangling quote
+/"/!bdqdone
+# otherwise, slurp next line and try again
N
s/\n//
-/"/!bdqstring
-bcheckchain
+bdqstring
+:dqdone
+s/@!/"/g
+bfolded
-# found multi-line single-quoted string '...\n...' -- slurp until end of string
+# check for multi-line single-quoted string '...\n...' -- fold to one line
:sqstring
-s/'//g
+# remove all quote pairs
+s/'\([^']*\)'/@!\1@!/g
+# done if no dangling quote
+/'/!bsqdone
+# otherwise, slurp next line and try again
N
s/\n//
-/'/!bsqstring
-bcheckchain
+bsqstring
+:sqdone
+s/@!/'/g
+bfolded
# found here-doc -- swallow it to avoid false hits within its body (but keep
-# the command to which it was attached); take care to handle here-docs nested
-# within here-docs by only recognizing closing tag matching outer here-doc
-# opening tag
+# the command to which it was attached)
:heredoc
-/EOF/{ s/[ ]*<<[ ]*[-\\]*EOF//; s/^/EOF/; }
-/EOT/{ s/[ ]*<<[ ]*[-\\]*EOT//; s/^/EOT/; }
-/INPUT_END/{ s/[ ]*<<[ ]*[-\\]*INPUT_END//; s/^/INPUT_END/; }
-:hereslurpsub
+s/^\(.*\)<<[ ]*[-\\'"]*\([A-Za-z0-9_][A-Za-z0-9_]*\)['"]*/<\2>\1<</
+s/[ ]*<<//
+:heredsub
N
-/^EOF.*\n[ ]*EOF[ ]*$/bhereclose
-/^EOT.*\n[ ]*EOT[ ]*$/bhereclose
-/^INPUT_END.*\n[ ]*INPUT_END[ ]*$/bhereclose
-bhereslurpsub
-:hereclose
-s/^EOF//
-s/^EOT//
-s/^INPUT_END//
+/^<\([^>]*\)>.*\n[ ]*\1[ ]*$/!{
+ s/\n.*$//
+ bheredsub
+}
+s/^<[^>]*>//
s/\n.*$//
-bcheckchain
+bfolded
# found "case ... in" -- pass through untouched
:case
# is 'done' or 'fi' cuddled with ")" to close subshell?
/done.*)/bclose
/fi.*)/bclose
-bcheckchain
+bchkchn
# found nested multi-line "(...\n...)" -- pass through untouched
:nest
x
-:nestslurp
+:nstslurp
n
# closing ")" on own line -- stop nested slurp
-/^[ ]*)/bnestclose
+/^[ ]*)/bnstclose
# comment -- not closing ")" if in comment
-/^[ ]*#/bnestcontinue
+/^[ ]*#/bnstcnt
# "$((...))" -- arithmetic expansion; not closing ")"
-/\$(([^)][^)]*))[^)]*$/bnestcontinue
+/\$(([^)][^)]*))[^)]*$/bnstcnt
# "$(...)" -- command substitution; not closing ")"
-/\$([^)][^)]*)[^)]*$/bnestcontinue
+/\$([^)][^)]*)[^)]*$/bnstcnt
# closing "...)" -- stop nested slurp
-/)/bnestclose
-:nestcontinue
+/)/bnstclose
+:nstcnt
x
-bnestslurp
-:nestclose
+bnstslurp
+:nstclose
s/^/>>/
# is it "))" which closes nested and parent subshells?
/)[ ]*)/bslurp
-bcheckchain
+bchkchn
# found multi-line "{...\n...}" block -- pass through untouched
:block
x
n
# closing "}" -- stop block slurp
-/}/bcheckchain
+/}/bchkchn
bblock
# found closing ")" on own line -- drop "suspect" from final line of subshell
# since that line legitimately lacks "&&" and exit subshell loop
-:closesolo
+:clssolo
x
s/?!AMP?!//
p