Add option to download packages by name regex

This patch adds a feature so that we can download sources for all packages
matching a regex.

For example

    butido source download --matching "perl5.34.0-.*"

for downloading all packages where their name matches "perl5.34.0-.*".

Signed-off-by: Matthias Beyer <matthias.beyer@atos.net>

2 files changed, 28 insertions, 5 deletions

diff --git a/src/cli.rs b/src/cli.rs
index 0da6745..2f58a6d 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -841,6 +841,20 @@ pub fn cli<'a>() -> App<'a> {
                     .long("force")
                     .about("Overwrite existing cache entry")
                 )
+
+                .arg(Arg::new("matching")
+                    .required(false)
+                    .multiple(false)
+                    .long("matching")
+                    .takes_value(true)
+                    .value_name("REGEX")
+                    .about("Download all packages matching a regex with their name")
+                )
+
+                .group(ArgGroup::new("download-one-or-many")
+                    .args(&["package_name", "matching"])
+                    .required(true)
+                )
             )
             .subcommand(App::new("of")
                 .version(crate_version!())
diff --git a/src/commands/source.rs b/src/commands/source.rs
index 52a0534..df3217f 100644
--- a/src/commands/source.rs
+++ b/src/commands/source.rs
@@ -285,14 +285,23 @@ pub async fn download(
         mp
     };
 
+    let matching_regexp = matches.value_of("matching")
+        .map(crate::commands::util::mk_package_name_regex)
+        .transpose()?;
+
     let r = repo
         .packages()
-        .filter(|p| pname.as_ref().map(|n| p.name() == n).unwrap_or(true))
         .filter(|p| {
-            pvers
-                .as_ref()
-                .map(|v| v.matches(p.version()))
-                .unwrap_or(true)
+            match (pname.as_ref(), pvers.as_ref(), matching_regexp.as_ref()) {
+                (None, None, None)              => true,
+                (Some(pname), None, None)       => p.name() == pname,
+                (Some(pname), Some(vers), None) => p.name() == pname && vers.matches(p.version()),
+                (None, None, Some(regex))       => regex.is_match(p.name()),
+
+                (_, _, _) => {
+                    panic!("This should not be possible, either we select packages by name and (optionally) version, or by regex.")
+                },
+            }
         })
         .map(|p| {
             sc.sources_for(p).into_iter().map(|source| {