One-shot environment variable assignments, such as 'FOO' in
"FOO=bar cmd", exist only during the invocation of 'cmd'. However, if
'cmd' happens to be a shell function, then 'FOO' is assigned in the
executing shell itself, and that assignment remains until the process
exits (unless explicitly unset). Since this side-effect of
"FOO=bar shell_func" is unlikely to be intentional, detect and report
such usage.
To distinguish shell functions from other commands, perform a pre-scan
of shell scripts named as input, gleaning a list of function names by
recognizing lines of the form (loosely matching whitespace):
shell_func () {
and later report suspect lines of the form (loosely matching quoted
values):
FOO=bar [BAR=foo ...] shell_func
Also take care to stitch together incomplete lines (those ending with
"\") since suspect invocations may be split over multiple lines:
FOO=bar BAR=foo \
shell_func
Signed-off-by: Eric Sunshine <sunshine@xxxxxxxxxxxxxx>
---
t/check-non-portable-shell.pl | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/t/check-non-portable-shell.pl b/t/check-non-portable-shell.pl
index f6dbe28b19..d5823f71d8 100755
--- a/t/check-non-portable-shell.pl
+++ b/t/check-non-portable-shell.pl
@@ -7,17 +7,34 @@
use warnings;
my $exit_code=0;
+my %func;
sub err {
my $msg = shift;
s/^\s+//;
s/\s+$//;
+ s/\s+/ /g;
print "$ARGV:$.: error: $msg: $_\n";
$exit_code = 1;
}
+# glean names of shell functions
+for my $i (@ARGV) {
+ open(my $f, '<', $i) or die "$0: $i: $!\n";
+ while (<$f>) {
+ $func{$1} = 1 if /^\s*(\w+)\s*\(\)\s*{\s*$/;
+ }
+ close $f;
+}
+
while (<>) {
chomp;
+ # stitch together incomplete lines (those ending with "\")
+ while (s/\\$//) {
+ $_ .= readline;
+ chomp;
+ }
+
/\bsed\s+-i/ and err 'sed -i is not portable';
/\becho\s+-[neE]/ and err 'echo with option is not portable (use printf)';
/^\s*declare\s+/ and err 'arrays/declare not portable';
@@ -25,6 +42,8 @@ sub err {
/\btest\s+[^=]*==/ and err '"test a == b" is not portable (use =)';
/\bwc -l.*"\s*=/ and err '`"$(wc -l)"` is not portable (use test_line_count)';
/\bexport\s+[A-Za-z0-9_]*=/ and err '"export FOO=bar" is not portable (use FOO=bar && export FOO)';
+ /^\s*([A-Z0-9_]+=(\w+|(["']).*?\3)\s+)+(\w+)/ and exists($func{$4}) and
+ err '"FOO=bar shell_func" assignment extends beyond "shell_func"';
# this resets our $. for each file
close ARGV if eof;
}
--
2.18.0.233.g985f88cf7e
