termination with set -e if a command fails in a loop body inside a function
with an explicitely tested exit status, eg
f() {
for i in 1 2 3; do
false
done
}
f || true
Briefly reviewed by: cracauer
two cases of unwanted termination with set -e:
* if-commands containing several commands separated by semicolons, eg
if false; false; then [...]
* functions with an explicitely tested exit status that contain a failing
command which is not the last one, eg
f() {
false
false
}
f || true
PR: 77067, 85267
Briefly reviewed by: cracauer
and linting procedure:
1. Remove useless sub-expression:
- if (*start || (!ifsspc && start > string && (nulonly || 1))) {
+ if (*start || (!ifsspc && start > string)) {
The sub-expression "(nulonly || 1)" always evaluates to true and
according to CVS logs seems to be just a left-over from some
debugging and introduced by accident. Removing the sub-expression
doesn't change semantics and a code inspection showed that the
variable "nulonly" is also not necessary here in any way (and the
expression would require fixing instead of removing).
2. Remove dead code:
- if (backslash && c == '\\') {
- if (read(STDIN_FILENO, &c, 1) != 1) {
- status = 1;
- break;
- }
- STPUTC(c, p);
- } else if (ap[1] != NULL && strchr(ifs, c) != NULL) {
+ if (ap[1] != NULL && strchr(ifs, c) != NULL) {
Inspection of the control and data flow showed that variable
"backslash" is always false (0) when the "if"-expression is
evaluated, hence the whole block is effectively dead code.
Additionally, the skipping of characters after a backslash is already
performed correctly a few lines above, so this code is also not
needed at all. According to the CVS logs and the ASH 0.2 sources,
this code existed in this way already since its early days.
3. Cleanup Style:
- ! trap[signo][0] == '\0' &&
+ ! (trap[signo][0] == '\0') &&
The expression wants to ensure the trap is not assigned the empty
string. But the "!" operator has higher precedence than "==", so the
comparison should be put into parenthesis to form the intended way of
expression. Nevertheless the code was effectively not really broken
as both particular NUL comparisons are semantically equal, of course.
But the parenthesized version is a lot more intuitive.
4. Remove shadowing variable declaration:
- char *q;
The declaration of symbol "q" hides another identical declaration of
"q" in the same context. As the other "q" is already reused multiple
times and also can be reused again without negative side-effects,
just remove the shadowing declaration.
5. Just small cosmetics:
- if (ifsset() != 0)
+ if (ifsset())
The ifsset() macro is already coded by returning the boolean result
of a comparison operator, so no need to compare this boolean result
again against a numerical value. This also aligns the macros usage to
the remaining existing code.
Reviewed by: stefanf@
converting the stat() call to a lstat() call, which will cover the
situation. One can exercise this bug by referring a dangling link with
something like */the-link.
Approved by: re (scottl)
Submitted by: Simon 'corecode' Schubert [corecode fs ei tum de]
Obtained from: NetBSD via DragonFlyBSD (NetBSD rev. 1.51 and DragonFly
rev. 1.6)
MFC After: 3 days
promised by the Argument List Processing section introduction.
What follows the option in the options list is its long name,
not its argument (as is the case for the -c option). Also
sort references in the SEE ALSO section.
Approved by: re (blanket)
benefit of scripts start out as: #!/bin/sh -- # -*- perl -*-
With this fix in place, we can commit a change to kern/imgact_shell.c
so FreeBSD will process the `#!' line in shell-scripts in a more
standard fashion.
PR: 16393
Mentioned on: freebsd-arch
- Move the description of the ``-c string'' option closer to the option itself.
- Add an ENVIRONMENT section (1)
- Add more .Xr cross references to the SEE ALSO section.
Obtained from: NetBSD (1)
work as expected when they have a "shebang line" of:
#!/bin/sh -- # -*- perl -*- -p
This specific line is recommended in some perl documentation, and I think
I've seen similar lines in documentation for ruby and python. Those
write-ups expect `sh' to ignore everything after the '--' if the first
thing after the '--' is a '#'. See chapter 19, "The Command-Line Interface"
in 3rd edition of "Programming Perl", for some discussion of why perl
recommends using this line in some circumstances.
The above line does work on solaris, irix and aix (as three data points),
and it used to work on FreeBSD by means of a similar patch to execve().
However, that change to execve() effected *all* shells (which caused
other problems), and that processing was recently removed.
PR: 16393 (the original request to fix the same issue)
Reviewed by: freebsd-current (looking at a slightly different patch)
MFC after: 1 week
XXX from Tor: "The shell can also go into a similar loop if the child was
killed by signal 127, since the shell would believe the child to have
only stopped (WIFSTOPPED() macro returns nonzero value). Disallowing
signals 127 and 128 will fix that problem." See kern/19402 for details.
PR: bin/66242
Submitted by: tegge
Analysis and testcase by: demon
MFC after: 3 weeks
instead of just !, this allows one to more easily locate/understand
the section of the manpage in question.
Additional wording correction by: keramida
Reviewed by: keramida
considered an error according to the Open Group Base Specification.
PR: standards/45738
Submitted by: Matthias Andree <matthias.andree@web.de>
MFC after: 3 days
