If an ; or & token was followed by an EOF token, pending here-documents were
left uninitialized. Execution would crash, either in the main shell process
for literal here-documents or in a child process for expanded
here-documents. In the latter case the problem is hard to detect apart from
the core dumps and log messages.
Side effect: slightly different retries on inputs where EOF is not
persistent.
Note that tools/regression/bin/sh/parser/heredoc6.0 still causes a similar
crash in a child process. The text passed to eval is malformed and should be
rejected.
simplecmd() only handles simple commands and function definitions, neither
of which involves the ! keyword. The initial token on entry to simplecmd()
is one of the following: TSEMI, TAND, TOR, TNL, TEOF, TWORD, TRP.
The LINENO code uses snprintf() and relied on "myhistedit.h" to pull in the
necessary <stdio.h>.
Compiling with -DNO_HISTORY disables all editing and history support and
allows linking without -ledit -ltermcap. This may be useful for embedded
systems.
MFC after: 2 weeks
Example (in interactive mode):
cat <<EOF && )
The next command typed caused sh to segfault, because the state for the here
document was not reset.
Like parser_temp, this uses the fact that the parser is not re-entered.
If a command substitution contains a newline token, this no longer starts
here documents of outer commands. This way, we follow POSIX's idea of the
command substitution being a separate script more closely. It also matches
other shells better and is consistent with newline characters in quotes not
starting here documents.
The extension tested in parser/heredoc3.0 ($(cat <<EOF)\ntext\nEOF\n)
continues to be supported.
In particular, this change allows things like
cat <<EOF && echo `pwd`
(a `` command substitution after a here document)
which formerly silently used an empty file as the here document, because the
EOF of the inner command "pwd" also forced an empty here document.
These do pretty much nothing (except that parentheses are ignored), but
people seem to use them and allowing them does not hurt much.
Single-quotes seem not to be used and cause silently different behaviour
with ksh93 character constants.
They will be treated like normal characters, resulting in a runtime
arithmetic expression error.
Exp-run done by: erwin (with some other sh(1) changes)
* remove the backslash from \} inside double quotes inside +-=?
substitutions, e.g. "${$+\}a}"
* maintain separate double-quote state for ${v#...} and ${v%...};
single and double quotes are special inside, even in a double-quoted
string or here document
* keep track of correct order of substitutions and arithmetic
This is different from dash's approach, which does not track individual
double quotes in the parser, trying to fix this up during expansion.
This treats single quotes inside "${v#...}" incorrectly, however.
This is similar to NetBSD's approach (as submitted in PR bin/57554), but
recognizes the difference between +-=? and #% substitutions hinted at in
POSIX and is more refined for arithmetic expansion and here documents.
PR: bin/57554
Exp-run done by: erwin (with some other sh(1) changes)
The old approach was wrong because PS2 was not used and seems unlikely to
parse extensions (ksh93's ${ COMMAND} may well fail to parse).
Exp-run done by: erwin (with some other sh(1) changes)
Make parsebackq a function instead of an emulated nested function.
This puts the setjmp usage in a smaller function where it is easier to avoid
bad optimizations.
- correctly handle error output in $(builtin 2>&1), clarify out1/out2 vs
output/errout in the code
- treat all builtins as regular builtins so errors do not abort the shell
and variable assignments do not persist
- respect the caller's INTOFF
Some bugs still exist:
- expansion errors may still abort the shell
- some side effects of expansions and builtins persist
* exception handlers are now run with interrupts disabled, which avoids
many race conditions
* fix some cases where SIGINT only aborts one command and continues the
script, in particular if a SIGINT causes an EINTR error which trumped the
interrupt.
Example:
sh -c 'echo < /some/fifo; echo This should not be printed'
The fifo should not have writers. When pressing ctrl+c to abort the open,
the shell used to continue with the next command.
Example:
sh -c '/bin/echo < /some/fifo; echo This should not be printed'
Similar. Note, however, that this particular case did not and does not work
in interactive mode with job control enabled.
* increase buffer size from 100 to 256 bytes
* remove implied flush from out2str(), in particular this avoids unnecessary
flushing in the middle of a -x tracing line
* rename dprintf() to out2fmt_flush(), make it flush out2 and use this
function in various places where flushing is desired after an error
message
the line number where the command substitution started.
This applies to both the $() and `` forms but is most useful for ``
because the other line number is relative to the enclosed text there.
(For older versions, -v can be used as a workaround.)
Due to the amount of code removed by this, it seems that allowing unmatched
quotes was a deliberate imitation of System V sh and real ksh. Most other
shells do not allow unmatched quotes (e.g. bash, zsh, pdksh, NetBSD /bin/sh,
dash).
PR: bin/137657
- remove ineffective and unnecessary (void) &var; [1]
- remove some unnecessary volatile keywords
- add a necessary volatile keyword
- save the old handler before doing something that could use the saved
value
Submitted by: Christoph Mallon [1]
Approved by: ed (mentor)
Portability Utilities" option.
Often configure scripts generated by the autotools test if $LINENO works and
refuse to use /bin/sh if not.
Package test run by: pav
issue a syntax error immediately but save the information that it is erroneous
for later when the parameter expansion is actually done. This means eg. "false
&& ${}" will not generate an error which seems to be required by POSIX.
Include the invalid parameter expansion in the error message (sometimes
abbreviated with ... because recovering it would require a lot of code).
PR: 105078
Submitted by: emaste
should slightly reduce the number of system calls in critical portions of
the shell, and select a more efficient path through the fdalloc code.
Reviewed by: bde
- Removed dead declarations
- Made objects that should have been declared as static, static.
The changes use STATIC instead of static, following the existing
convention in the rest of the code.
Approved by: schweikh (mentor)
MFC after: 2 weeks
commands. Commands like "if then ... fi" and "while do ... done" are no
longer accepted. Bodies of compound commands are still allowed to be
empty, because even though POSIX does not allow them, most shells do.
adding history and vi/emacs-style line editing to the shell itself.
Atty was a user-mode terminal emulator (like screen and window) that did
line editing and history.
o Old-style K&R declarations have been converted to new C89 style
o register has been removed
o prototype for main() has been removed (gcc3 makes it an error)
o int main(int argc, char *argv[]) is the preferred main definition.
o Attempt to not break style(9) conformance for declarations more than
they already are.
o Change
int
foo() {
...
to
int
foo(void)
{
...
