feat: Add --exclude option for host exclusion (pdsh -x compatibility)

ARCHITECTURE.md

@@ -88,7 +88,7 @@ See "Issue #33 Refactoring Details" section below for comprehensive breakdown.
 - `main.rs` - Clean entry point (69 lines)
 - `app/dispatcher.rs` - Command routing and dispatch (368 lines)
 - `app/initialization.rs` - App initialization and config loading (206 lines)
-- `app/nodes.rs` - Node resolution and filtering (242 lines)
+- `app/nodes.rs` - Node resolution, filtering, and exclusion (587 lines)
 - `app/cache.rs` - Cache statistics and management (142 lines)
 - `app/query.rs` - SSH query options handler (58 lines)
 - `app/utils.rs` - Utility functions (62 lines)

README.md

@@ -182,6 +182,11 @@ bssh -C production "df -h"
 bssh -H "web1,web2,db1,db2" -f "web*" "systemctl status nginx"
 bssh -C production -f "db*" "pg_dump --version"
 
+# Exclude specific hosts from execution
+bssh -H "node1,node2,node3" --exclude "node2" "uptime"
+bssh -C production --exclude "db*" "systemctl restart nginx"
+bssh -C production --exclude "web1,web2" "apt update"
+
 # With custom SSH key
 bssh -C staging -i ~/.ssh/custom_key "systemctl status nginx"
 
@@ -915,7 +920,9 @@ bssh -F ~/.ssh/prod-config -C production upload app.tar.gz /opt/
 ```
 Options:
   -H, --hosts <HOSTS>                     Comma-separated list of hosts (user@host:port format)
-  -c, --cluster <CLUSTER>                 Cluster name from configuration file
+  -C, --cluster <CLUSTER>                 Cluster name from configuration file
+  -f, --filter <PATTERN>                  Filter hosts by pattern (supports wildcards like 'web*')
+  --exclude <HOSTS>                       Exclude hosts from target list (comma-separated, supports wildcards)
   --config <CONFIG>                       Configuration file path [default: ~/.config/bssh/config.yaml]
   -u, --user <USER>                       Default username for SSH connections
   -i, --identity <IDENTITY>               SSH private key file path (prompts for passphrase if encrypted)

docs/man/bssh.1

@@ -170,6 +170,27 @@ Filter hosts by pattern (supports wildcards like 'web*').
 Use with -H or -C to execute on a subset of hosts.
 Example: -f "web*" matches web01, web02, etc.
 
+.TP
+.BR \-\-exclude " " \fIHOSTS\fR
+Exclude hosts from target list (comma-separated).
+Supports wildcard patterns: '*' (any chars), '?' (single char), '[abc]' (char set).
+Patterns with wildcards use glob matching; plain patterns use substring matching.
+Applied after --filter option.
+.RS
+.PP
+Examples:
+.IP \[bu] 2
+--exclude "node2" - Exclude single host
+.IP \[bu] 2
+--exclude "web1,web2" - Exclude multiple hosts
+.IP \[bu] 2
+--exclude "db*" - Exclude hosts starting with 'db'
+.IP \[bu] 2
+--exclude "*-backup" - Exclude backup nodes
+.IP \[bu] 2
+--exclude "web[12]" - Exclude web1 and web2
+.RE
+
 .TP
 .BR \-\-parallel " " \fIPARALLEL\fR
 Maximum parallel connections for multi-server mode (default: 10)
@@ -1051,6 +1072,25 @@ Executes command only on hosts matching the pattern 'web*'
 Executes command only on database nodes in the production cluster
 .RE
 
+.TP
+Exclude specific hosts from execution:
+.B bssh -H "node1,node2,node3" --exclude "node2" "uptime"
+.RS
+Executes command on node1 and node3, excluding node2
+.RE
+
+.TP
+.B bssh -C production --exclude "db*" "systemctl restart nginx"
+.RS
+Executes command on all production hosts except database servers
+.RE
+
+.TP
+.B bssh -C production --exclude "web1,web2" "apt update"
+.RS
+Excludes specific hosts web1 and web2 from the cluster operation
+.RE
+
 .TP
 Test connectivity:
 .B bssh -C production ping