* `nix-env -q' now accepts arguments that allow specific derivations

to be queried, e.g., `nix-env -qa firefox'.  This does require the
  argument '*' to be passed if one wants information about all
  derivations, so the old `nix-env -qa' now is `nix-env -qa "*"'.

src/nix-env/main.cc

@@ -217,19 +217,21 @@ static DrvInfos filterBySelector(EvalState & state,
     DrvNames selectors = drvNamesFromArgs(args);
 
     DrvInfos elems;
-    PathSet done;
+    set<unsigned int> done;
 
     for (DrvNames::iterator i = selectors.begin();
          i != selectors.end(); ++i)
     {
-        DrvInfos matches;
+        typedef list<pair<DrvInfo, unsigned int> > Matches;
+        Matches matches;
+        unsigned int n = 0;
         for (DrvInfos::const_iterator j = allElems.begin();
-             j != allElems.end(); ++j)
+             j != allElems.end(); ++j, ++n)
         {
             DrvName drvName(j->name);
             if (i->matches(drvName)) {
                 i->hits++;
-                matches.push_back(*j);
+                matches.push_back(pair<DrvInfo, unsigned int>(*j, n));
             }
         }
 
@@ -240,40 +242,37 @@ static DrvInfos filterBySelector(EvalState & state,
         if (newestOnly) {
 
             /* Map from package names to derivations. */
-            map<string, DrvInfo> newest;
+            typedef map<string, pair<DrvInfo, unsigned int> > Newest;
+            Newest newest;
             StringSet multiple;
 
-            for (DrvInfos::const_iterator j = matches.begin();
+            for (Matches::iterator j = matches.begin(); j != matches.end(); ++j) {
-                 j != matches.end(); ++j)
+                DrvName drvName(j->first.name);
-            {
+                Newest::iterator k = newest.find(drvName.name);
-                DrvName drvName(j->name);
-                map<string, DrvInfo>::iterator k = newest.find(drvName.name);
                 if (k != newest.end()) {
-                    int d = compareVersions(drvName.version, DrvName(k->second.name).version);
+                    int d = compareVersions(drvName.version, DrvName(k->second.first.name).version);
                     if (d > 0) newest[drvName.name] = *j;
-                    else if (d == 0) multiple.insert(j->name);
+                    else if (d == 0) multiple.insert(j->first.name);
                 } else
                     newest[drvName.name] = *j;
             }
 
             matches.clear();
-            for (map<string, DrvInfo>::iterator j = newest.begin();
+            for (Newest::iterator j = newest.begin(); j != newest.end(); ++j) {
-                 j != newest.end(); ++j) {
+                if (multiple.find(j->second.first.name) != multiple.end())
-                if (multiple.find(j->second.name) != multiple.end())
                     printMsg(lvlInfo,
                         format("warning: there are multiple derivations named `%1%'; using the first one")
-                        % j->second.name);
+                        % j->second.first.name);
                 matches.push_back(j->second);
             }
         }
 
         /* Insert only those elements in the final list that we
            haven't inserted before. */
-        for (DrvInfos::const_iterator j = matches.begin();
+        for (Matches::iterator j = matches.begin(); j != matches.end(); ++j)
-             j != matches.end(); ++j)
+            if (done.find(j->second) == done.end()) {
-            if (done.find(j->queryOutPath(state)) == done.end()) {
+                done.insert(j->second);
-                done.insert(j->queryOutPath(state));
+                elems.push_back(j->first);
-                elems.push_back(*j);
             }
     }
             
@@ -718,7 +717,9 @@ static void opQuery(Globals & globals,
         else if (*i == "--available" || *i == "-a") source = sAvailable;
         else throw UsageError(format("unknown flag `%1%'") % *i);
 
-    if (opArgs.size() != 0) throw UsageError("no arguments expected");
+    if (opArgs.size() == 0) {
+        printMsg(lvlInfo, "warning: you probably meant to specify the argument '*' to show all packages");
+    }
 
     
     /* Obtain derivation information from the specified source. */
@@ -733,7 +734,10 @@ static void opQuery(Globals & globals,
             globals.instSource.systemFilter, availElems);
     }
 
-    DrvInfos & elems(source == sInstalled ? installedElems : availElems);
+    DrvInfos elems = filterBySelector(globals.state,
+        source == sInstalled ? installedElems : availElems,
+        opArgs, false);
+    
     DrvInfos & otherElems(source == sInstalled ? availElems : installedElems);
 
     

tests/user-envs.sh

@@ -6,19 +6,19 @@ profiles="$NIX_STATE_DIR"/profiles
 test "$($nixenv -p $profiles/test -q | wc -l)" -eq 0
 
 # Query available: should contain several.
-test "$($nixenv -p $profiles/test -f ./user-envs.nix -qa | wc -l)" -eq 5
+test "$($nixenv -p $profiles/test -f ./user-envs.nix -qa '*' | wc -l)" -eq 5
 
 # Install "foo-1.0".
 $nixenv -p $profiles/test -f ./user-envs.nix -i foo-1.0
 
 # Query installed: should contain foo-1.0 now (which should be
 # executable).
-test "$($nixenv -p $profiles/test -q | wc -l)" -eq 1
+test "$($nixenv -p $profiles/test -q '*' | wc -l)" -eq 1
-$nixenv -p $profiles/test -q | grep -q foo-1.0
+$nixenv -p $profiles/test -q '*' | grep -q foo-1.0
 test "$($profiles/test/bin/foo)" = "foo-1.0"
 
 # Store the path of foo-1.0.
-outPath10=$($nixenv -p $profiles/test -q --out-path --no-name | grep foo-1.0)
+outPath10=$($nixenv -p $profiles/test -q --out-path --no-name '*' | grep foo-1.0)
 echo "foo-1.0 = $outPath10"
 test -n "$outPath10"
 
@@ -26,20 +26,20 @@ test -n "$outPath10"
 $nixenv -p $profiles/test -f ./user-envs.nix -i foo-2.0pre1
 
 # Query installed: should contain foo-2.0pre1 now.
-test "$($nixenv -p $profiles/test -q | wc -l)" -eq 1
+test "$($nixenv -p $profiles/test -q '*' | wc -l)" -eq 1
-$nixenv -p $profiles/test -q | grep -q foo-2.0pre1
+$nixenv -p $profiles/test -q '*' | grep -q foo-2.0pre1
 test "$($profiles/test/bin/foo)" = "foo-2.0pre1"
 
 # Upgrade "foo": should install foo-2.0.
 $nixenv -p $profiles/test -f ./user-envs.nix -u foo
 
 # Query installed: should contain foo-2.0 now.
-test "$($nixenv -p $profiles/test -q | wc -l)" -eq 1
+test "$($nixenv -p $profiles/test -q '*' | wc -l)" -eq 1
-$nixenv -p $profiles/test -q | grep -q foo-2.0
+$nixenv -p $profiles/test -q '*' | grep -q foo-2.0
 test "$($profiles/test/bin/foo)" = "foo-2.0"
 
 # Store the path of foo-2.0.
-outPath20=$($nixenv -p $profiles/test -q --out-path --no-name | grep foo-2.0)
+outPath20=$($nixenv -p $profiles/test -q --out-path --no-name '*' | grep foo-2.0)
 test -n "$outPath20"
 
 # Install bar-0.1, uninstall foo.
@@ -47,18 +47,18 @@ $nixenv -p $profiles/test -f ./user-envs.nix -i bar-0.1
 $nixenv -p $profiles/test -f ./user-envs.nix -e foo
 
 # Query installed: should only contain bar-0.1 now.
-if $nixenv -p $profiles/test -q | grep -q foo; then false; fi
+if $nixenv -p $profiles/test -q '*' | grep -q foo; then false; fi
-$nixenv -p $profiles/test -q | grep -q bar
+$nixenv -p $profiles/test -q '*' | grep -q bar
 
 # Rollback: should bring "foo" back.
 $nixenv -p $profiles/test --rollback
-$nixenv -p $profiles/test -q | grep -q foo-2.0
+$nixenv -p $profiles/test -q '*' | grep -q foo-2.0
-$nixenv -p $profiles/test -q | grep -q bar
+$nixenv -p $profiles/test -q '*' | grep -q bar
 
 # Rollback again: should remove "bar".
 $nixenv -p $profiles/test --rollback
-$nixenv -p $profiles/test -q | grep -q foo-2.0
+$nixenv -p $profiles/test -q '*' | grep -q foo-2.0
-if $nixenv -p $profiles/test -q | grep -q bar; then false; fi
+if $nixenv -p $profiles/test -q '*' | grep -q bar; then false; fi
 
 # Count generations.
 test "$($nixenv -p $profiles/test --list-generations | wc -l)" -eq 5
@@ -66,7 +66,7 @@ test "$($nixenv -p $profiles/test --list-generations | wc -l)" -eq 5
 # Install foo-1.0, now using its store path.
 echo $outPath10
 $nixenv -p $profiles/test -i "$outPath10"
-$nixenv -p $profiles/test -q | grep -q foo-1.0
+$nixenv -p $profiles/test -q '*' | grep -q foo-1.0
 
 # Delete all old generations.
 $nixenv -p $profiles/test --delete-generations old
@@ -79,12 +79,12 @@ if test -e "$outPath20"; then false; fi
 
 # Uninstall everything
 $nixenv -p $profiles/test -f ./user-envs.nix -e '*'
-test "$($nixenv -p $profiles/test -q | wc -l)" -eq 0
+test "$($nixenv -p $profiles/test -q '*' | wc -l)" -eq 0
 
 # Installing "foo" should only install the newest foo.
 $nixenv -p $profiles/test -f ./user-envs.nix -i foo
-test "$($nixenv -p $profiles/test -q | grep foo- | wc -l)" -eq 1
+test "$($nixenv -p $profiles/test -q '*' | grep foo- | wc -l)" -eq 1
-$nixenv -p $profiles/test -q | grep -q foo-2.0
+$nixenv -p $profiles/test -q '*' | grep -q foo-2.0
 
 # On the other hand, this should install both (and should fail due to
 # a collision).
@@ -94,6 +94,6 @@ if $nixenv -p $profiles/test -f ./user-envs.nix -i foo-1.0 foo-2.0; then false;
 # Installing "*" should install one foo and one bar.
 $nixenv -p $profiles/test -f ./user-envs.nix -e '*'
 $nixenv -p $profiles/test -f ./user-envs.nix -i '*'
-test "$($nixenv -p $profiles/test -q | wc -l)" -eq 2
+test "$($nixenv -p $profiles/test -q '*' | wc -l)" -eq 2
-$nixenv -p $profiles/test -q | grep -q foo-2.0
+$nixenv -p $profiles/test -q '*' | grep -q foo-2.0
-$nixenv -p $profiles/test -q | grep -q bar-0.1.1
+$nixenv -p $profiles/test -q '*' | grep -q bar-0.1.1