parallel: Basic --completion implemented for bash.

src/parallel

@@ -1558,10 +1558,16 @@ sub shell_completion() {
     if($opt::completion eq "zsh") {
 	# if(shell == zsh);
 	zsh_competion();
+    } elsif($opt::completion eq "bash") {
+	# if(shell == bash);
+	bash_competion();
     } elsif($opt::completion eq "auto") {
 	if($Global::shell =~ m:/zsh$|^zsh$:) {
 	    # if(shell == zsh);
 	    zsh_competion();
+	} elsif($Global::shell =~ m:/bash$|^bash$:) {
+	    # if(shell == bash);
+	    bash_competion();
 	} else {
 	    ::error("--completion is not implemented for '$Global::shell'.");
 	    wait_and_exit(255);
@@ -1572,6 +1578,39 @@ sub shell_completion() {
     }
 }
 
+sub bash_competion() {
+    # Print:
+    #   complete -F _comp_parallel parallel;
+    #   _comp_parallel() {
+    #     COMPREPLY=($(compgen -W "--options" --
+    #                    "${COMP_WORDS[$COMP_CWORD]}"));
+    #   };
+    my @bash_completion =
+	("complete -F _comp_parallel parallel;",
+	 '_comp_parallel() { COMPREPLY=($(compgen -W "');
+    my @och = options_completion_hash();
+    while(@och) {
+	$_ = shift @och;
+	# Split input like:
+	# "joblog|jl=s[Logfile for executed jobs]:logfile:_files"
+	if(/^(.*?)(\[.*?])?(:[^:]*)?(:.*)?$/) {
+	    my $opt = $1;
+	    my $desc = $2;
+	    my $argdesc = $3;
+	    my $func = $4;
+	    # opt=s => opt
+	    $opt =~ s/[:=].$//;
+	    push @bash_completion,
+		(map { (length $_ == 1) ? "-$_ " : "--$_ " }
+				split /\|/, $opt);
+
+	}
+	shift @och;
+    }
+    push @bash_completion,'" -- "${COMP_WORDS[$COMP_CWORD]}")); };'."\n";
+    print @bash_completion;
+}
+
 sub zsh_competion() {
     my @zsh_completion =
 	("compdef _comp_parallel parallel; ",
@@ -1584,7 +1623,7 @@ sub zsh_competion() {
 	$_ = shift @och;
 	# Split input like:
 	# "joblog|jl=s[Logfile for executed jobs]:logfile:_files"
-	if(/^(.*?)(\[.*?])(:[^:]*)?(:.*)?$/) {
+	if(/^(.*?)(\[.*?])?(:[^:]*)?(:.*)?$/) {
 	    my $opt = $1;
 	    my $desc = $2;
 	    my $argdesc = $3;
@@ -2542,7 +2581,7 @@ sub check_invalid_option_combinations() {
 
 sub init_globals() {
     # Defaults:
-    $Global::version = 20220331;
+    $Global::version = 20220401;
     $Global::progname = 'parallel';
     $::name = "GNU Parallel";
     $Global::infinity = 2**31;

src/parallel.pod

@@ -778,13 +778,14 @@ See also: B<--csv> B<{>I<n>B<}> B<--trim> B<--link>
 
 Generate shell completion code for interactive shells.
 
-Supported shells: zsh.
+Supported shells: bash zsh.
 
 Use I<auto> as I<shell> to automatically detect running shell.
 
 Activate the completion code with:
 
   zsh% eval "`parallel --completion auto`"
+  bash$ eval "`parallel --completion auto`"
 
 
 =item B<--compress>

testsuite/tests-to-run/parallel-local-0.3s.sh

@@ -16,6 +16,15 @@ export -f stdsort
 # Test amount of parallelization
 # parallel --shuf --jl /tmp/myjl -j1 'export JOBS={1};'bash tests-to-run/parallel-local-0.3s.sh ::: {1..16} ::: {1..5}
 
+par_completion() {
+    echo '### --completion'
+    # This will change, if you change options
+    parallel --completion bash | md5sum
+    bash -c 'parallel --completion auto;true' | md5sum
+    parallel --completion zsh | md5sum
+    zsh -c 'parallel --completion auto;true' | md5sum
+}    
+
 par_ctagstring() {
     echo '### --ctag --ctagstring should be different from --tag --tagstring'
     parallel --tag echo ::: 1 ::: a| wc -c

testsuite/wanted-results/parallel-local-0.3s

@@ -62,6 +62,11 @@ par_colsep_0	OK
 par_colsep_0	OK
 par_colsep_default	bug #37956: --colsep does not default to '\t' as specified in the man page.
 par_colsep_default	one 1
+par_completion	### --completion
+par_completion	857e87c031164f28c4ec91e610c8cff7  -
+par_completion	857e87c031164f28c4ec91e610c8cff7  -
+par_completion	09b6d6d121bc9542589aca39741e5390  -
+par_completion	09b6d6d121bc9542589aca39741e5390  -
 par_compress_stdout_stderr	### Test compress - stdout
 par_compress_stdout_stderr	OK
 par_compress_stdout_stderr	### Test compress - stderr