diff options
| -rw-r--r-- | src/nix-env/help.txt | 4 | ||||
| -rw-r--r-- | src/nix-env/main.cc | 59 | ||||
| -rw-r--r-- | src/nix-env/profiles.hh | 8 |
3 files changed, 71 insertions, 0 deletions
diff --git a/src/nix-env/help.txt b/src/nix-env/help.txt index 3832f1655b4e..9a772fc8330a 100644 --- a/src/nix-env/help.txt +++ b/src/nix-env/help.txt @@ -13,6 +13,10 @@ The previous operations take a list of derivation names. The special name `*' may be used to indicate all derivations. --switch-profile / -S [FILE]: switch to specified profile + --switch-generation / -G NUMBER: switch to specified generation of profile + --rollback: switch to the previous generation + --list-generations: list available generations of a profile + --import / -I FILE: set default Nix expression --version: output version information diff --git a/src/nix-env/main.cc b/src/nix-env/main.cc index 5ef61bb306a0..69b3fdd9c5cf 100644 --- a/src/nix-env/main.cc +++ b/src/nix-env/main.cc @@ -472,6 +472,61 @@ static void opSwitchProfile(Globals & globals, } +static const int prevGen = -2; + + +static void switchGeneration(Globals & globals, int dstGen) +{ + int curGen; + Generations gens = findGenerations(globals.profile, curGen); + + Generation dst; + for (Generations::iterator i = gens.begin(); i != gens.end(); ++i) + if ((dstGen == prevGen && i->number < curGen) || + (dstGen >= 0 && i->number == dstGen)) + dst = *i; + + if (!dst) + if (dstGen == prevGen) + throw Error(format("no generation older than the current (%1%) exists") + % curGen); + else + throw Error(format("generation %1% does not exist") % dstGen); + + switchLink(globals.profile, dst.path); +} + + +static void opSwitchGeneration(Globals & globals, + Strings opFlags, Strings opArgs) +{ + if (opFlags.size() > 0) + throw UsageError(format("unknown flag `%1%'") % opFlags.front()); + if (opArgs.size() != 1) + throw UsageError(format("exactly one argument expected")); + + istringstream str(opArgs.front()); + int dstGen; + str >> dstGen; + if (!str || !str.eof()) + throw UsageError(format("expected a generation number")); + + switchGeneration(globals, dstGen); +} + + +static void opRollback(Globals & globals, + Strings opFlags, Strings opArgs) +{ + if (opFlags.size() > 0) + throw UsageError(format("unknown flag `%1%'") % opFlags.front()); + if (opArgs.size() != 0) + throw UsageError(format("no arguments expected")); + + switchGeneration(globals, prevGen); +} + + static void opListGenerations(Globals & globals, Strings opFlags, Strings opArgs) { @@ -550,6 +605,10 @@ void run(Strings args) } else if (arg == "--switch-profile" || arg == "-S") op = opSwitchProfile; + else if (arg == "--switch-generation" || arg == "-G") + op = opSwitchGeneration; + else if (arg == "--rollback") + op = opRollback; else if (arg == "--list-generations") op = opListGenerations; else if (arg[0] == '-') diff --git a/src/nix-env/profiles.hh b/src/nix-env/profiles.hh index 2422c9f7425a..2ce468dfa837 100644 --- a/src/nix-env/profiles.hh +++ b/src/nix-env/profiles.hh @@ -11,6 +11,14 @@ struct Generation int number; Path path; time_t creationTime; + Generation() + { + number = -1; + } + operator bool() const + { + return number != -1; + } }; typedef list<Generation> Generations; |