3 * This file is part of LyX, the document processor.
4 * Licence details can be found in the file COPYING.
6 * \author Ruurd A. Reitsma
7 * \author Enrico Forestieri
9 * Full author contact details are available in file CREDITS.
14 #include "support/convert.h"
15 #include "support/debug.h"
16 #include "support/filetools.h"
17 #include "support/qstring_helpers.h"
18 #include "support/regex.h"
22 #if defined(__CYGWIN__)
23 #include "support/os_cygwin.cpp"
25 #include "support/os_win32.cpp"
27 #include "support/os_unix.cpp"
30 // Static assert to break compilation on platforms where
31 // int/unsigned int is not 4 bytes. Added to make sure that
32 // e.g., the author hash is always 32-bit.
33 template<bool Condition> struct static_assert_helper;
34 template <> struct static_assert_helper<true> {};
36 dummy = sizeof(static_assert_helper<sizeof(int) == 4>)
49 static string const python23_call(string const & binary, bool verbose = false)
51 const string version_info = " -c 'from __future__ import print_function;import sys; print(sys.version_info[:2], end=\"\")'";
52 static regex const python_reg("\\((\\d*), (\\d*)\\)");
53 // Default to "python" if no binary is given.
58 lyxerr << "Examining " << binary << "\n";
59 // Check whether this is a python 2 or 3 binary.
60 cmd_ret const out = runCommand(binary + version_info);
63 if (out.first < 0 || !regex_match(out.second, sm, python_reg))
66 int major = convert<int>(sm.str(1));
67 int minor = convert<int>(sm.str(2));
68 if((major == 2 && minor < 7) || (major == 3 && minor < 5))
72 lyxerr << "Found Python " << out.second << "\n";
73 // Add the -tt switch so that mixed tab/whitespace
74 // indentation is an error
75 return binary + " -tt";
79 static string const find_python_binary()
81 // This function takes inspiration from PEP 394 and PEP 397
82 // PEP 394 -- The "python" Command on Unix-Like Systems
83 // https://www.python.org/dev/peps/pep-0394/
84 // PEP 397 -- Python launcher for Windows
85 // https://www.python.org/dev/peps/pep-0397/
87 // Check whether python3 in PATH is the right one.
88 string command = python23_call("python3");
92 // python3 does not exists, let us try to find python3.x in PATH
93 // the search is probably broader than required
94 // but we are trying hard to find a valid python binary
95 vector<string> const path = getEnvPath("PATH");
96 lyxerr << "Looking for python 3.x ...\n";
97 for (auto bin: path) {
98 QString const dir = toqstr(bin);
99 string const localdir = dir.toLocal8Bit().constData();
101 qdir.setFilter(QDir::Files | QDir::Executable);
102 QStringList list = qdir.entryList(QStringList("python3*"));
103 for (auto bin: list) {
104 string const binary = addName(localdir,
105 bin.toLocal8Bit().constData());
106 command = python23_call(binary, true);
107 if (!command.empty())
112 // python 3 was not found let us look for python 2
113 command = python23_call("python2");
114 if (!command.empty())
117 // python2 does not exists, let us try to find python2.x in PATH
118 // the search is probably broader than required
119 // but we are trying hard to find a valid python binary
120 lyxerr << "Looking for python 2.x ...\n";
121 for (auto bin: path) {
122 QString const dir = toqstr(bin);
123 string const localdir = dir.toLocal8Bit().constData();
125 qdir.setFilter(QDir::Files | QDir::Executable);
126 QStringList list = qdir.entryList(QStringList("python2*"));
127 for (auto bin: list) {
128 string const binary = addName(localdir,
129 bin.toLocal8Bit().constData());
130 command = python23_call(binary, true);
131 if (!command.empty())
136 // If this happens all hope is lost that this is a sane system
137 lyxerr << "Warning: No python v2.x or 3.x binary found.\n";
138 return python23_call("");
142 string const python(bool reset)
144 static string command = find_python_binary();
147 command = find_python_binary();
153 } // namespace support