87394a9e0b
We were having child processes SIGSTOP themselves immediately after setting their process group and before launching their intended targets, but they were not necessarily stopped by the time the next command was being executed (so the opposite of the original race condition where they might have finished executing by the time the next command came around), and as a result when we sent them SIGCONT, that could never reach. Now using waitpid to synchronize the SIGSTOP/SIGCONT between the two. If we had a good, unnamed inter-process event/semaphore, we could use that to have a child process conditionally stop itself if the next command in the job chain hadn't yet been started / setup, but this is probably a lot more straightforward and less-confusing, which isn't a bad thing. Additionally, there was a bug caused by the fact that the main exec_job loop actually blocks to read from previous commands in the job if the current command is a built-in that doesn't need to fork. With this waitpid code, I was able to finally add the SIGSTOP code to all the fork'd processes in the main exec_job loop without introducing deadlocks; it turns out that they should be treated just like the main EXTERNAL fork, but they tend to execute faster causing the same deadlock described above to occur more readily. The only thing I'm not sure about is whether we should execute unblock_pid undconditionally for all !EXTERNAL commands. It makes more sense to *only* do that if a blocking read were about to be done in the main loop, otherwise the original race condition could still appear (though it is probably mitigated by whatever duration the SIGSTOP lasted for, even if it is SIGCONT'd before the next command tries to join the process group). |
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| .github | ||
| build_tools | ||
| debian | ||
| doc_src | ||
| etc | ||
| fish.xcodeproj | ||
| m4 | ||
| osx | ||
| pcre2-10.22 | ||
| po | ||
| share | ||
| src | ||
| tests | ||
| .clang-format | ||
| .cppcheck.rules | ||
| .cppcheck.suppressions | ||
| .editorconfig | ||
| .gitattributes | ||
| .gitignore | ||
| .oclint | ||
| .travis.yml | ||
| CHANGELOG.md | ||
| config.guess | ||
| config.sub | ||
| configure.ac | ||
| CONTRIBUTING.md | ||
| COPYING | ||
| Dockerfile | ||
| Doxyfile | ||
| Doxyfile.help | ||
| Doxyfile.user | ||
| fish.pc.in | ||
| fish.spec.in | ||
| install-sh | ||
| lexicon_filter.in | ||
| Makefile.in | ||
| README.md | ||
fish - the friendly interactive shell 
fish is a smart and user-friendly command line shell for OS X, Linux, and the rest of the family. fish includes features like syntax highlighting, autosuggest-as-you-type, and fancy tab completions that just work, with no configuration required.
For more on fish's design philosophy, see the design document.
Quick Start
fish generally works like other shells, like bash or zsh. A few important differences can be found at https://fishshell.com/docs/current/tutorial.html by searching for the magic phrase "unlike other shells".
Detailed user documentation is available by running help within fish, and also at https://fishshell.com/docs/current/index.html
Building
fish requires a C++11 compiler. It builds successfully with g++ 4.8 or later, or with clang 3.3 or later.
fish can be built using autotools or Xcode. autoconf 2.60 or later, as well as automake 1.13 or later, are required to build from git versions. These are not required to build from released tarballs.
fish depends on a curses implementation, such as ncurses. The headers and libraries are required for building.
fish requires PCRE2 due to the regular expression support contained in the string builtin. A copy is included with the source code, and will be used automatically if it does not already exist on your system.
fish requires gettext for translation support.
Building the documentation requires Doxygen 1.8.7 or newer.
Autotools Build
autoreconf --no-recursive [if building from Git]
./configure
make [gmake on BSD]
sudo make install [sudo gmake install on BSD]
Xcode Development Build
- Build the
basetarget in Xcode - Run the fish executable, for example, in
DerivedData/fish/Build/Products/Debug/base/bin/fish
Xcode Build and Install
xcodebuild install
sudo ditto /tmp/fish.dst /
sudo make install-doc
Help, it didn't build!
If fish reports that it could not find curses, try installing a curses development package and build again.
On Debian or Ubuntu you want:
sudo apt-get install build-essential ncurses-dev libncurses5-dev gettext autoconf
On RedHat, CentOS, or Amazon EC2:
sudo yum install ncurses-devel
Runtime Dependencies
fish requires a curses implementation, such as ncurses, to run.
fish requires PCRE2 due to the regular expression support contained in the string builtin. A bundled version will be compiled in automatically at build time if required.
fish requires a number of utilities to operate, which should be present on any Unix, GNU/Linux or OS X system. These include (but are not limited to) hostname, grep, awk, sed, and getopt. fish also requires the bc program.
Translation support requires the gettext program.
Usage output for builtin functions is generated on-demand from the installed manpages using nroff and ul.
Some optional features of fish, such as the manual page completion parser and the web configuration tool, require Python.
In order to generate completions from man pages compressed with either lzma or xz, you may need to install an extra Python package. Python versions prior to 2.6 are not supported. To process lzma-compresed manpages, backports.lzma is needed for Python 3.2 or older. From version 3.3 onwards, Python already includes the required module.
Packages for Linux
Instructions on how to find builds for several Linux distros are at https://github.com/fish-shell/fish-shell/wiki/Nightly-builds
Switching to fish
If you wish to use fish as your default shell, use the following command:
chsh -s /usr/local/bin/fish
chsh will prompt you for your password, and change your default shell. Substitute "/usr/local/bin/fish" with whatever path to fish is in your /etc/shells file.
Use the following command if you didn't already add your fish path to /etc/shells.
echo /usr/local/bin/fish | sudo tee -a /etc/shells
To switch your default shell back, you can run:
chsh -s /bin/bash
Substitute /bin/bash with /bin/tcsh or /bin/zsh as appropriate.
You may need to logout/login for the change (chsh) to take effect.
Contributing Changes to the Code
See the Guide for Developers.
Contact Us
Questions, comments, rants and raves can be posted to the official fish mailing list at https://lists.sourceforge.net/lists/listinfo/fish-users or join us on our gitter.im channel or IRC channel #fish at irc.oftc.net. Or use the fish tag on Stackoverflow for questions related to fish script and the fish tag on Superuser for all other questions (e.g., customizing colors, changing key bindings).
Found a bug? Have an awesome idea? Please open an issue on this github page.