Add support for -c/--command option to execute commands and exit

AUTHORS

@@ -145,6 +145,7 @@ Contributors:
     * fbdb
     * Charbel Jacquin (charbeljc)
     * Jeronimo Garcia (bechampion)
+    * Diego
     * Devadathan M B (devadathanmb)
     * Charalampos Stratakis
     * Laszlo Bimba (bimlas)

changelog.rst

@@ -34,6 +34,9 @@ Features:
     * Support dsn specific init-command in the config file
 * Add suggestion when setting the search_path
 * Allow per dsn_alias ssh tunnel selection
+* Add support for `single-command` to run a SQL command and exit.
+    * Command line option `-c` or `--command`.
+    * You can specify multiple times.
 
 Internal:
 ---------

pgcli/main.py

@@ -959,6 +959,25 @@ def _check_ongoing_transaction_and_allow_quitting(self):
     def run_cli(self):
         logger = self.logger
 
+        # Handle command mode (-c flag) - similar to psql behavior
+        # Multiple -c options are executed sequentially
+        if hasattr(self, 'commands') and self.commands:
+            try:
+                for command in self.commands:
+                    logger.debug("Running command: %s", command)
+                    # Execute the command using the same logic as interactive mode
+                    self.handle_watch_command(command)
+            except PgCliQuitError:
+                # Normal exit from quit command
+                sys.exit(0)
+            except Exception as e:
+                logger.error("Error executing command: %s", e)
+                logger.error("traceback: %r", traceback.format_exc())
+                click.secho(str(e), err=True, fg="red")
+                sys.exit(1)
+            # Exit successfully after executing all commands
+            sys.exit(0)
+
         history_file = self.config["main"]["history_file"]
         if history_file == "default":
             history_file = config_location() + "history"
@@ -1340,7 +1359,8 @@ def is_too_tall(self, lines):
         return len(lines) >= (self.prompt_app.output.get_size().rows - 4)
 
     def echo_via_pager(self, text, color=None):
-        if self.pgspecial.pager_config == PAGER_OFF or self.watch_command:
+        # Disable pager for -c/--command mode and \watch command
+        if self.pgspecial.pager_config == PAGER_OFF or self.watch_command or (hasattr(self, 'commands') and self.commands):
             click.echo(text, color=color)
         elif self.pgspecial.pager_config == PAGER_LONG_OUTPUT and self.table_format != "csv":
             lines = text.split("\n")
@@ -1488,6 +1508,13 @@ def echo_via_pager(self, text, color=None):
     type=str,
     help="SQL statement to execute after connecting.",
 )
+@click.option(
+    "-c",
+    "--command",
+    "commands",
+    multiple=True,
+    help="run command (SQL or internal) and exit. Multiple -c options are allowed.",
+)
 @click.argument("dbname", default=lambda: None, envvar="PGDATABASE", nargs=1)
 @click.argument("username", default=lambda: None, envvar="PGUSER", nargs=1)
 def cli(
@@ -1516,6 +1543,7 @@ def cli(
     ssh_tunnel: str,
     init_command: str,
     log_file: str,
+    commands: tuple,
 ):
     if version:
         print("Version:", __version__)
@@ -1576,6 +1604,9 @@ def cli(
         log_file=log_file,
     )
 
+    # Store commands for -c option (can be multiple)
+    pgcli.commands = commands if commands else None
+
     # Choose which ever one has a valid value.
     if dbname_opt and dbname:
         # work as psql: when database is given as option and argument use the argument as user

tests/features/command_option.feature

@@ -0,0 +1,38 @@
+Feature: run the cli with -c/--command option,
+  execute a single command,
+  and exit
+
+  Scenario: run pgcli with -c and a SQL query
+     When we run pgcli with -c "SELECT 1 as test_column"
+      then we see the query result
+      and pgcli exits successfully
+
+  Scenario: run pgcli with --command and a SQL query
+     When we run pgcli with --command "SELECT 'hello' as greeting"
+      then we see the query result
+      and pgcli exits successfully
+
+  Scenario: run pgcli with -c and a special command
+     When we run pgcli with -c "\dt"
+      then we see the command output
+      and pgcli exits successfully
+
+  Scenario: run pgcli with -c and an invalid query
+     When we run pgcli with -c "SELECT invalid_column FROM nonexistent_table"
+      then we see an error message
+      and pgcli exits successfully
+
+  Scenario: run pgcli with -c and multiple statements
+     When we run pgcli with -c "SELECT 1; SELECT 2"
+      then we see both query results
+      and pgcli exits successfully
+
+  Scenario: run pgcli with multiple -c options
+     When we run pgcli with multiple -c options
+      then we see all command outputs
+      and pgcli exits successfully
+
+  Scenario: run pgcli with mixed -c and --command options
+     When we run pgcli with mixed -c and --command
+      then we see all command outputs
+      and pgcli exits successfully

tests/features/steps/command_option.py

@@ -0,0 +1,198 @@
+"""
+Steps for testing -c/--command option behavioral tests.
+"""
+
+import subprocess
+from behave import when, then
+
+
+@when('we run pgcli with -c "{command}"')
+def step_run_pgcli_with_c(context, command):
+    """Run pgcli with -c flag and a command."""
+    cmd = [
+        "pgcli",
+        "-h",
+        context.conf["host"],
+        "-p",
+        str(context.conf["port"]),
+        "-U",
+        context.conf["user"],
+        "-d",
+        context.conf["dbname"],
+        "-c",
+        command,
+    ]
+    try:
+        context.cmd_output = subprocess.check_output(cmd, cwd=context.package_root, stderr=subprocess.STDOUT, timeout=5)
+        context.exit_code = 0
+    except subprocess.CalledProcessError as e:
+        context.cmd_output = e.output
+        context.exit_code = e.returncode
+    except subprocess.TimeoutExpired:
+        context.cmd_output = b"Command timed out"
+        context.exit_code = -1
+
+
+@when('we run pgcli with --command "{command}"')
+def step_run_pgcli_with_command(context, command):
+    """Run pgcli with --command flag and a command."""
+    cmd = [
+        "pgcli",
+        "-h",
+        context.conf["host"],
+        "-p",
+        str(context.conf["port"]),
+        "-U",
+        context.conf["user"],
+        "-d",
+        context.conf["dbname"],
+        "--command",
+        command,
+    ]
+    try:
+        context.cmd_output = subprocess.check_output(cmd, cwd=context.package_root, stderr=subprocess.STDOUT, timeout=5)
+        context.exit_code = 0
+    except subprocess.CalledProcessError as e:
+        context.cmd_output = e.output
+        context.exit_code = e.returncode
+    except subprocess.TimeoutExpired:
+        context.cmd_output = b"Command timed out"
+        context.exit_code = -1
+
+
+@then("we see the query result")
+def step_see_query_result(context):
+    """Verify that the query result is in the output."""
+    output = context.cmd_output.decode('utf-8')
+    # Check for common query result indicators
+    assert any([
+        "SELECT" in output,
+        "test_column" in output,
+        "greeting" in output,
+        "hello" in output,
+        "+-" in output,  # table border
+        "|" in output,  # table column separator
+    ]), f"Expected query result in output, but got: {output}"
+
+
+@then("we see both query results")
+def step_see_both_query_results(context):
+    """Verify that both query results are in the output."""
+    output = context.cmd_output.decode('utf-8')
+    # Should contain output from both SELECT statements
+    assert "SELECT" in output, f"Expected SELECT in output, but got: {output}"
+    # The output should have multiple result sets
+    assert output.count("SELECT") >= 2, f"Expected at least 2 SELECT results, but got: {output}"
+
+
+@then("we see the command output")
+def step_see_command_output(context):
+    """Verify that the special command output is present."""
+    output = context.cmd_output.decode('utf-8')
+    # `\dt` renders its column headers whether or not any tables exist, so the
+    # headers are what tells us the special command actually ran and produced
+    # its listing (rather than erroring out).
+    for header in ("Schema", "Name", "Type", "Owner"):
+        assert header in output, f"Expected {header!r} in \\dt output, but got: {output}"
+    assert context.exit_code == 0, f"Expected exit code 0, but got: {context.exit_code}"
+
+
+@then("we see an error message")
+def step_see_error_message(context):
+    """Verify that an error message is in the output."""
+    output = context.cmd_output.decode('utf-8')
+    assert any([
+        "does not exist" in output,
+        "error" in output.lower(),
+        "ERROR" in output,
+    ]), f"Expected error message in output, but got: {output}"
+
+
+@then("pgcli exits successfully")
+def step_pgcli_exits_successfully(context):
+    """Verify that pgcli exited with code 0."""
+    assert context.exit_code == 0, f"Expected exit code 0, but got: {context.exit_code}"
+    # Clean up
+    context.cmd_output = None
+    context.exit_code = None
+
+
+@then("pgcli exits with error")
+def step_pgcli_exits_with_error(context):
+    """Verify that pgcli exited with a non-zero code."""
+    assert context.exit_code != 0, f"Expected non-zero exit code, but got: {context.exit_code}"
+    # Clean up
+    context.cmd_output = None
+    context.exit_code = None
+
+
+@when("we run pgcli with multiple -c options")
+def step_run_pgcli_with_multiple_c(context):
+    """Run pgcli with multiple -c flags."""
+    cmd = [
+        "pgcli",
+        "-h",
+        context.conf["host"],
+        "-p",
+        str(context.conf["port"]),
+        "-U",
+        context.conf["user"],
+        "-d",
+        context.conf["dbname"],
+        "-c",
+        "SELECT 'first' as result",
+        "-c",
+        "SELECT 'second' as result",
+        "-c",
+        "SELECT 'third' as result",
+    ]
+    try:
+        context.cmd_output = subprocess.check_output(cmd, cwd=context.package_root, stderr=subprocess.STDOUT, timeout=10)
+        context.exit_code = 0
+    except subprocess.CalledProcessError as e:
+        context.cmd_output = e.output
+        context.exit_code = e.returncode
+    except subprocess.TimeoutExpired:
+        context.cmd_output = b"Command timed out"
+        context.exit_code = -1
+
+
+@when("we run pgcli with mixed -c and --command")
+def step_run_pgcli_with_mixed_options(context):
+    """Run pgcli with mixed -c and --command flags."""
+    cmd = [
+        "pgcli",
+        "-h",
+        context.conf["host"],
+        "-p",
+        str(context.conf["port"]),
+        "-U",
+        context.conf["user"],
+        "-d",
+        context.conf["dbname"],
+        "-c",
+        "SELECT 'from_c' as source",
+        "--command",
+        "SELECT 'from_command' as source",
+    ]
+    try:
+        context.cmd_output = subprocess.check_output(cmd, cwd=context.package_root, stderr=subprocess.STDOUT, timeout=10)
+        context.exit_code = 0
+    except subprocess.CalledProcessError as e:
+        context.cmd_output = e.output
+        context.exit_code = e.returncode
+    except subprocess.TimeoutExpired:
+        context.cmd_output = b"Command timed out"
+        context.exit_code = -1
+
+
+@then("we see all command outputs")
+def step_see_all_command_outputs(context):
+    """Verify that all command outputs are present."""
+    output = context.cmd_output.decode('utf-8')
+    # Should contain output from all commands
+    assert "first" in output or "from_c" in output, f"Expected 'first' or 'from_c' in output, but got: {output}"
+    assert "second" in output or "from_command" in output, f"Expected 'second' or 'from_command' in output, but got: {output}"
+    # For the 3-command test, also check for third
+    if "third" in output or "result" in output:
+        assert "third" in output, f"Expected 'third' in output for 3-command test, but got: {output}"