diff options
| -rwxr-xr-x | bin/sbang | 84 | ||||
| -rw-r--r-- | lib/spack/llnl/util/filesystem.py | 11 | ||||
| -rw-r--r-- | lib/spack/spack/hooks/sbang.py | 77 |
3 files changed, 171 insertions, 1 deletions
diff --git a/bin/sbang b/bin/sbang new file mode 100755 index 0000000000..ebfbe2e7a1 --- /dev/null +++ b/bin/sbang @@ -0,0 +1,84 @@ +#!/bin/bash +# +# `sbang`: Run scripts with long shebang lines. +# +# Many operating systems limit the length of shebang lines, making it +# hard to use interpreters that are deep in the directory hierarchy. +# `sbang` can run such scripts, either as a shebang interpreter, or +# directly on the command line. +# +# Usage +# ----------------------------- +# Suppose you have a script, long-shebang.sh, like this: +# +# 1 #!/very/long/path/to/some/interpreter +# 2 +# 3 echo "success!" +# +# Invoking this script will result in an error on some OS's. On +# Linux, you get this: +# +# $ ./long-shebang.sh +# -bash: ./long: /very/long/path/to/some/interp: bad interpreter: +# No such file or directory +# +# On Mac OS X, the system simply assumes the interpreter is the shell +# and tries to run with it, which is likely not what you want. +# +# +# `sbang` on the command line +# ----------------------------- +# You can use `sbang` in two ways. The first is to use it directly, +# from the command line, like this: +# +# $ sbang ./long-shebang.sh +# success! +# +# +# `sbang` as the interpreter +# ----------------------------- +# You can also use `sbang` *as* the interpreter for your script. Put +# `#!/bin/bash /path/to/sbang` on line 1, and move the original +# shebang to line 2 of the script: +# +# 1 #!/bin/bash /path/to/sbang +# 2 #!/long/path/to/real/interpreter with arguments +# 3 +# 4 echo "success!" +# +# $ ./long-shebang.sh +# success! +# +# On Linux, you could shorten line 1 to `#!/path/to/sbang`, but other +# operating systems like Mac OS X require the interpreter to be a +# binary, so it's best to use `sbang` as a `bash` argument. +# Obviously, for this to work, `sbang` needs to have a short enough +# path that *it* will run without hitting OS limits. +# +# +# How it works +# ----------------------------- +# `sbang` is a very simple bash script. It looks at the first two +# lines of a script argument and runs the last line starting with +# `#!`, with the script as an argument. It also forwards arguments. +# + +# First argument is the script we want to actually run. +script="$1" + +# Search the first two lines of script for interpreters. +lines=0 +while read line && ((lines < 2)) ; do + if [[ "$line" = '#!'* ]]; then + interpreter="${line#\#!}" + fi + lines=$((lines+1)) +done < "$script" + +# Invoke any interpreter found, or raise an error if none was found. +if [ -n "$interpreter" ]; then + exec $interpreter "$@" +else + echo "error: sbang found no interpreter in $script" + exit 1 +fi diff --git a/lib/spack/llnl/util/filesystem.py b/lib/spack/llnl/util/filesystem.py index a92cb0706d..9ba662d0e3 100644 --- a/lib/spack/llnl/util/filesystem.py +++ b/lib/spack/llnl/util/filesystem.py @@ -25,7 +25,8 @@ __all__ = ['set_install_permissions', 'install', 'install_tree', 'traverse_tree', 'expand_user', 'working_dir', 'touch', 'touchp', 'mkdirp', 'force_remove', 'join_path', 'ancestor', 'can_access', 'filter_file', - 'FileFilter', 'change_sed_delimiter', 'is_exe', 'force_symlink', 'remove_dead_links', 'remove_linked_tree'] + 'FileFilter', 'change_sed_delimiter', 'is_exe', 'force_symlink', + 'remove_dead_links', 'remove_linked_tree', 'copy_mode', 'unset_executable_mode'] import os import sys @@ -158,6 +159,14 @@ def copy_mode(src, dest): os.chmod(dest, dest_mode) +def unset_executable_mode(path): + mode = os.stat(path).st_mode + mode &= ~stat.S_IXUSR + mode &= ~stat.S_IXGRP + mode &= ~stat.S_IXOTH + os.chmod(path, mode) + + def install(src, dest): """Manually install a file to a particular location.""" tty.debug("Installing %s to %s" % (src, dest)) diff --git a/lib/spack/spack/hooks/sbang.py b/lib/spack/spack/hooks/sbang.py new file mode 100644 index 0000000000..3390ecea29 --- /dev/null +++ b/lib/spack/spack/hooks/sbang.py @@ -0,0 +1,77 @@ +############################################################################## +# Copyright (c) 2013-2015, Lawrence Livermore National Security, LLC. +# Produced at the Lawrence Livermore National Laboratory. +# +# This file is part of Spack. +# Written by Todd Gamblin, tgamblin@llnl.gov, All rights reserved. +# LLNL-CODE-647188 +# +# For details, see https://github.com/llnl/spack +# Please also see the LICENSE file for our notice and the LGPL. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License (as published by +# the Free Software Foundation) version 2.1 dated February 1999. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and +# conditions of the GNU General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with this program; if not, write to the Free Software Foundation, +# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +############################################################################## +import os + +from llnl.util.filesystem import * +import llnl.util.tty as tty + +import spack +import spack.modules + +# Character limit for shebang line. Using Linux's 127 characters +# here, as it is the shortest I could find on a modern OS. +shebang_limit = 127 + +def shebang_too_long(path): + """Detects whether an file has a shebang line that is too long.""" + with open(path, 'r') as script: + bytes = script.read(2) + if bytes != '#!': + return False + + line = bytes + script.readline() + return len(line) > shebang_limit + + +def filter_shebang(path): + """Adds a second shebang line, using sbang, at the beginning of a file.""" + backup = path + ".shebang.bak" + os.rename(path, backup) + + with open(backup, 'r') as bak_file: + original = bak_file.read() + + with open(path, 'w') as new_file: + new_file.write('#!/bin/bash %s/bin/sbang\n' % spack.spack_root) + new_file.write(original) + + copy_mode(backup, path) + unset_executable_mode(backup) + + tty.warn("Patched overly long shebang in %s" % path) + + +def post_install(pkg): + """This hook edits scripts so that they call /bin/bash + $spack_prefix/bin/sbang instead of something longer than the + shebang limit.""" + if not os.path.isdir(pkg.prefix.bin): + return + + for file in os.listdir(pkg.prefix.bin): + path = os.path.join(pkg.prefix.bin, file) + if shebang_too_long(path): + filter_shebang(path) + |