ERR trap inheritance in command substitution
Hi!
It seems that in bash version 4.0.33(1)-release (i486-pc-linux-gnu) (from Ubuntu
9.04), ERR traps are not inherited by functions that are called via command
substitution. I expected inheritance to apply in this case since the
documentation of 'set -E' promises inheritance of the ERR trap for subshell
contexts. The script below illustrates this behavior as the trap action
err_handler() is not called.
Is this behaviour intended? Even if so, I'd like to say that I would find ERR
trap inheritance for command substitution extremely useful :-)
Cheers,
Stefan
#!/bin/bash
err_handler() {
echo "THERE WAS AN ERROR"
}
set -E
trap 'err_handler' ERR
myfunc() {
false # fails to cause an ERR trap
true
}
FOO=$(myfunc)
exit 0
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Told to report this bug here.
Hello, I downloaded the bash-80 file from Apple and encountered this configuration error: checking wchar.h usability... no checking wchar.h presence... yes configure: WARNING: wchar.h: present but cannot be compiled configure: WARNING: wchar.h: check for missing prerequisite headers? configure: WARNING: wchar.h: see the Autoconf documentation configure: WARNING: wchar.h: section "Present But Cannot Be Compiled" configure: WARNING: wchar.h: proceeding with the preprocessor's result configure: WARNING: wchar.h: in the future, the compiler will take precedence configure: WARNING: ## --- ## configure: WARNING: ## Report this to bug-bash@gnu.org ## configure: WARNING: ## --- ## checking for wchar.h... yes when trying to build using the following command: make SDKROOT="/Developer/SDKs/MacOSX10.6.sdk/" RC_ARCHS="ppc". Extracted from config.log is the following: configure:15416: checking wchar.h usability configure:15428: gcc -c -arch ppc -g -Os -pipe -no-cpp-precomp - mdynamic-no-pic -DM_UNIX -DSSH_SOURCE_BASHRC -isysroot /Developer/SDKs/ MacOSX10.6.sdk/ conftest.c >&5 In file included from /Developer/SDKs/MacOSX10.6.sdk//usr/include/ wchar.h:111, from conftest.c:264: /Developer/SDKs/MacOSX10.6.sdk//usr/include/stdarg.h:4:25: error: stdarg.h: No such file or directory configure:15434: $? = 1 configure: failed program was: | /* confdefs.h. */ | | #define PACKAGE_NAME "bash" | #define PACKAGE_TARNAME "bash" | #define PACKAGE_VERSION "3.2-release" | #define PACKAGE_STRING "bash 3.2-release" | #define PACKAGE_BUGREPORT "bug-bash@gnu.org" | #define ALIAS 1 | #define PUSHD_AND_POPD 1 | #define RESTRICTED_SHELL 1 | #define PROCESS_SUBSTITUTION 1 | #define PROMPT_STRING_DECODE 1 | #define SELECT_COMMAND 1 | #define HELP_BUILTIN 1 | #define ARRAY_VARS 1 | #define DPAREN_ARITHMETIC 1 | #define BRACE_EXPANSION 1 | #define COMMAND_TIMING 1 | #define EXTENDED_GLOB 1 | #define COND_COMMAND 1 | #define COND_REGEXP 1 | #define ARITH_FOR_COMMAND 1 | #define NETWORK_REDIRECTIONS 1 | #define PROGRAMMABLE_COMPLETION 1 | #define DEBUGGER 1 | #define MEMSCRAMBLE 1 | #define HAVE_SYS_TYPES_H 1 | #define HAVE_SYS_STAT_H 1 | #define HAVE_STDLIB_H 1 | #define HAVE_STRING_H 1 | #define HAVE_MEMORY_H 1 | #define HAVE_STRINGS_H 1 | #define HAVE_INTTYPES_H 1 | #define HAVE_STDINT_H 1 | #define HAVE_UNISTD_H 1 | #define READLINE 1 | #define HISTORY 1 | #define BANG_HISTORY 1 | #define _GNU_SOURCE 1 | #define HAVE_STRINGIZE 1 | #define HAVE_ALLOCA_H 1 | #define HAVE_ALLOCA 1 | #define HAVE_STDLIB_H 1 | #define HAVE_UNISTD_H 1 | #define HAVE_GETPAGESIZE 1 | #define HAVE_MMAP 1 | #define INTDIV0_RAISES_SIGFPE 0 | #define HAVE_INTTYPES_H_WITH_UINTMAX 1 | #define HAVE_STDINT_H_WITH_UINTMAX 1 | #define HAVE_UNSIGNED_LONG_LONG 1 | #define HAVE_UINTMAX_T 1 | #define HAVE_INTTYPES_H 1 | #define HAVE_LIMITS_H 1 | #define HAVE_LOCALE_H 1 | #define HAVE_NL_TYPES_H 1 | #define HAVE_STDDEF_H 1 | #define HAVE_STDLIB_H 1 | #define HAVE_STRING_H 1 | #define HAVE_UNISTD_H 1 | #define HAVE_SYS_PARAM_H 1 | #define HAVE_FEOF_UNLOCKED 1 | #define HAVE_GETC_UNLOCKED 1 | #define HAVE_GETCWD 1 | #define HAVE_GETEGID 1 | #define HAVE_GETEUID 1 | #define HAVE_GETGID 1 | #define HAVE_GETUID 1 | #define HAVE_MUNMAP 1 | #define HAVE_PUTENV 1 | #define HAVE_SETENV 1 | #define HAVE_SETLOCALE 1 | #define HAVE_STPCPY 1 | #define HAVE_STRCASECMP 1 | #define HAVE_STRDUP 1 | #define HAVE_STRTOUL 1 | #define HAVE_TSEARCH 1 | #define HAVE_ICONV 1 | #define ICONV_CONST | #define HAVE_LANGINFO_CODESET 1 | #define HAVE_LC_MESSAGES 1 | #define ENABLE_NLS 1 | #define HAVE_DIRENT_H 1 | #define TIME_WITH_SYS_TIME 1 | #define HAVE_INTTYPES_H 1 | #define HAVE_UNISTD_H 1 | #define HAVE_STDLIB_H 1 | #define HAVE_STDARG_H 1 | #define HAVE_LIMITS_H 1 | #define HAVE_STRING_H 1 | #define HAVE_MEMORY_H 1 | #define HAVE_LOCALE_H 1 | #define HAVE_TERMCAP_H 1 | #define HAVE_TERMIOS_H 1 | #define HAVE_DLFCN_H 1 | #define HAVE_STDDEF_H 1 | #define HAVE_STDINT_H 1 | #define HAVE_NETDB_H 1 | #define HAVE_PWD_H 1 | #define HAVE_GRP_H 1 | #define HAVE_STRINGS_H 1 | #define HAVE_REGEX_H 1 | #define HAVE_SYS_SELECT_H 1 | #define HAVE_SYS_FILE_H 1 | #define HAVE_SYS_RESOURCE_H 1 | #define HAVE_SYS_PARAM_H 1 | #define HAVE_SYS_SOCKET_H 1 | #define HAVE_SYS_STAT_H 1 | #define HAVE_SYS_TIME_H 1 | #define HAVE_SYS_TIMES_H 1 | #define HAVE_SYS_TYPES_H 1 | #define HAVE_SYS_WAIT_H 1 | #define HAVE_NETINET_IN_H 1 | #define HAVE_ARPA_INET_H 1 | #define HAVE_ALLOCA_H 1 | #define HAVE_ALLOCA 1 | #define GETPGRP_VOID 1 | #define SETVBUF_REVERSED 1 | #define HAVE_VPRINTF 1 | #define HAVE_STRCOLL 1 | #define RETSIGTYPE void | #define HAVE_WAIT3 1 | #define HAVE_ISINF_IN_LIBC 1 | #define HAVE_ISNAN_IN_LIBC 1 | #define HAVE_MKFIFO 1 |
Re: Told to report this bug here.
On 1/8/10 3:50 PM, Frank J. R. Hanstick wrote: > Hello, > I downloaded the bash-80 file from Apple and encountered this > configuration error: Aside from the fact that the bash-80 tar file available from Apple is packaged by Apple, this doesn't exactly look like a bash problem: > configure:15416: checking wchar.h usability > configure:15428: gcc -c -arch ppc -g -Os -pipe -no-cpp-precomp > -mdynamic-no-pic -DM_UNIX -DSSH_SOURCE_BASHRC -isysroot > /Developer/SDKs/MacOSX10.6.sdk/ conftest.c >&5 > In file included from > /Developer/SDKs/MacOSX10.6.sdk//usr/include/wchar.h:111, > from conftest.c:264: > /Developer/SDKs/MacOSX10.6.sdk//usr/include/stdarg.h:4:25: error: > stdarg.h: No such file or directory I build bash-3.x and 4.x on Mac OS X 10.5.x all the time (though not specifying the 10.6 SDK). You might consider downloading the official distribution from gnu.org. Chet -- ``The lyf so short, the craft so long to lerne.'' - Chaucer ``Ars longa, vita brevis'' - Hippocrates Chet Ramey, ITS, CWRUc...@case.eduhttp://cnswww.cns.cwru.edu/~chet/
Re: ERR trap inheritance in command substitution
On 1/8/10 12:50 PM, Stefan Götz wrote:
> Hi!
>
> It seems that in bash version 4.0.33(1)-release (i486-pc-linux-gnu) (from
> Ubuntu
> 9.04), ERR traps are not inherited by functions that are called via command
> substitution. I expected inheritance to apply in this case since the
> documentation of 'set -E' promises inheritance of the ERR trap for subshell
> contexts. The script below illustrates this behavior as the trap action
> err_handler() is not called.
>
> Is this behaviour intended? Even if so, I'd like to say that I would find ERR
> trap inheritance for command substitution extremely useful :-)
>
> Cheers,
> Stefan
>
> #!/bin/bash
>
> err_handler() {
> echo "THERE WAS AN ERROR"
> }
>
> set -E
> trap 'err_handler' ERR
>
> myfunc() {
> false # fails to cause an ERR trap
> true
> }
>
> FOO=$(myfunc)
> exit 0
How does this script demonstrate that err_handler is not called? The
command substitution swallows all the output, and you never look at
the results.
Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRUc...@case.eduhttp://cnswww.cns.cwru.edu/~chet/
missing dep in lib/glob/Makefile.in
lib/glob/glob.c uses shell.h and pathnames.h
--- bash-4.1/lib/glob/Makefile.in
+++ bash-4.1/lib/glob/Makefile.in
@@ -119,6 +119,11 @@
mostlyclean: clean
-( cd doc && $(MAKE) $(MFLAGS) $@ )
+# Dependencies
+
+${BUILD_DIR}/pathnames.h: ${BUILD_DIR}/config.h ${BUILD_DIR}/Makefile Makefile
+ -( cd ${BUILD_DIR} && ${MAKE} ${MFLAGS} pathnames.h )
+
##
# #
# Dependencies for the object files which make up this library. #
@@ -136,7 +141,7 @@
strmatch.o: $(BUILD_DIR)/config.h
strmatch.o: $(BASHINCDIR)/stdc.h
-glob.o: $(BUILD_DIR)/config.h
+glob.o: $(BUILD_DIR)/config.h $(topdir)/shell.h $(BUILD_DIR)/pathnames.h
glob.o: $(topdir)/bashtypes.h $(BASHINCDIR)/ansi_stdlib.h $(topdir)/bashansi.h
glob.o: $(BASHINCDIR)/posixstat.h $(BASHINCDIR)/memalloc.h
glob.o: strmatch.h glob.h
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Re: ulimit and ssh?
Thanks Bob. All the explanation were very helpful. Now I feel I have a good understanding of this little peculiarity of ssh. I agree with you that avoiding quoting altogether is simpler. But I am curious guy and learning for the sake of better understanding is also important to me. Bob Proulx wrote: > > peter360 wrote: >> Thanks Adreas. That was what I suspected in my reply to Bob. But Bob >> disagreed. Looks like there were some confusion about this feature even >> among experts. Seems another reason to deprecate the feature. > > I don't think anything I said disagreed with what Andreas said. It is > just confusing you since we are talking about different points in the > process. What does the local shell do, what does the ssh do, what > does the remote shell do, what is the end-to-end effect and so forth. > All three processes are handling the arguments and each has an affect > at different points in the timeline. I was talking end-to-end > (shell-ssh-shell) and Andreas was talking about ssh. > > And by the way but this feature can't really be changed or it would > break twenty years or so of scripts which rely upon the existing > behavior. > > Greg Wooledge wrote: >> imadev:~$ $HOME/bin/args 'ulimit -a' >> 1 args: 'ulimit -a' >> imadev:~$ remsh localhost $HOME/bin/args 'ulimit -a' >> 2 args: 'ulimit' '-a' >> imadev:~$ ssh localhost $HOME/bin/args 'ulimit -a' >> wool...@localhost's password: >> 2 args: 'ulimit' '-a' > > Nice! It would also be illustrative to show what happens without any > quoting and with quoting for two shell layers. > > $ $HOME/bin/show-args 'ulimit -a' > arg1: ulimit -a > > $ ssh -n localhost $HOME/bin/show-args ulimit -a > arg1: ulimit > arg2: -a > > $ ssh -n localhost $HOME/bin/show-args 'ulimit -a' > arg1: ulimit > arg2: -a > > $ ssh -n localhost $HOME/bin/show-args '"ulimit -a"' > arg1: ulimit -a > > Since there are two shells splitting words in the end-to-end result > then the effect is that you need to quote your arguments twice in > order to have an argument containing whitespace in one argument by the > time it has been processed through two shell's argument processing. > > Without sufficient quoting you have this following case, which isn't > what you want. The bash shell on the remote end would not see args > "-c" "ulimit -a" but would see "-a" as a separate > > $ ssh -n localhost $HOME/bin/show-args bash -c "ulimit -a" > arg1: bash > arg2: -c > arg3: ulimit > arg4: -a > > That isn't what you want. You need to quote the args twice. > > $ ssh -n localhost $HOME/bin/show-args 'bash -c "ulimit -a"' > arg1: bash > arg2: -c > arg3: ulimit -a > > In the end you want something like this: > > $ ssh -n localhost 'bash -c "ulimit -a"' > core file size (blocks, -c) 0 > data seg size (kbytes, -d) unlimited > scheduling priority (-e) 0 > file size (blocks, -f) unlimited > pending signals (-I) 8185 > max locked memory (kbytes, -l) 32 > max memory size (kbytes, -m) unlimited > open files (-n) 1024 > pipe size(512 bytes, -p) 8 > POSIX message queues (bytes, -q) 819200 > real-time priority (-r) 0 > stack size (kbytes, -s) 8192 > cpu time (seconds, -t) unlimited > max user processes (-u) 8185 > virtual memory (kbytes, -v) unlimited > file locks (-x) unlimited > > However I think it is simpler to avoid the argument processing and > instead using stdin to the shell. > > $ echo ulimit -a | ssh localhost bash > > Isn't that simpler? > > Bob > > > > -- View this message in context: http://old.nabble.com/ulimit-and-ssh--tp25262471p27086055.html Sent from the Gnu - Bash mailing list archive at Nabble.com.
