catch incompatible --clean flag when no operation is specified with better error message (#2644)

* improve error messaging when running yay -c

* use correct method in parsing -c flag

* better express prefixes in --help

clean.go

@@ -52,7 +52,7 @@ func syncClean(ctx context.Context, run *runtime.Runtime, cmdArgs *parser.Argume
 	keepInstalled := false
 	keepCurrent := false
 
-	_, removeAll, _ := cmdArgs.GetArg("c", "clean")
+	removeAll := cmdArgs.ExistsArg("c", "clean")
 
 	for _, v := range run.PacmanConf.CleanMethod {
 		switch v {

cmd.go

@@ -51,7 +51,7 @@ New operations:
     yay {-Y --yay}         [options] [package(s)]
 
 If no operation is specified 'yay -Syu' will be performed
-If no operation is specified and targets are provided -Y will be assumed
+If no operation is specified and targets are provided, -Y will be assumed
 
 New options:
     -N --repo             Assume targets are from the repositories
@@ -122,18 +122,18 @@ Permanent configuration options:
 
     --timeupdate          Check packages' AUR page for changes during sysupgrade
 
-show specific options:
+show specific options (used with -P):
     -c --complete         Used for completions
     -d --defaultconfig    Print default yay configuration
     -g --currentconfig    Print current yay configuration
     -s --stats            Display system package statistics
     -w --news             Print arch news
 
-yay specific options:
+yay specific options (used with -Y):
     -c --clean            Remove unneeded dependencies (-cc to ignore optdepends)
        --gendb            Generates development package DB used for updating
 
-getpkgbuild specific options:
+getpkgbuild specific options (used with -G):
     -f --force            Force download for existing ABS packages
     -p --print            Print pkgbuild of packages`)
 }

pkg/settings/parser/parser.go

@@ -542,7 +542,7 @@ func hasParam(arg string) bool {
 }
 
 // Parses short hand options such as:
-// -Syu -b/some/path -.
+// -Syu -b /some/path -.
 func (a *Arguments) parseShortOption(arg, param string) (usedNext bool, err error) {
 	if arg == "-" {
 		err = a.AddArg("-")
@@ -655,6 +655,14 @@ func (a *Arguments) Parse() error {
 		if len(a.Targets) > 0 {
 			a.Op = "Y"
 		} else {
+			// Handle args incompatible with -Syu
+			if a.ExistsArg("c", "clean") {
+				fmt.Println(gotext.Get("the clean command requires an operation to be specified"))
+				fmt.Println(gotext.Get("did you mean yay -Scc (clean caches) or yay -Ycc (clean orphaned packages)?"))
+
+				return errors.New(gotext.Get("invalid option"))
+			}
+
 			if _, err := a.parseShortOption("-Syu", ""); err != nil {
 				return err
 			}