Automatically suppress line prompts when stdin is redirected

[Copilot]

This PR addresses the issue where line prompts (like "1>", "2>", "3>") appear in the output when running sqlcmd as a subprocess from another program.

The solution automatically detects when stdin is redirected (from pipes or files) and suppresses line prompts in those cases, while preserving interactive behavior when running in a terminal.

Changes

• Added stdin redirection detection in pkg/console/console_redirect.go
• Modified console initialization to skip prompts when stdin is redirected
• Preserved interactive mode with prompts when running in a terminal
• Added tests for stdin redirection detection

This matches the behavior of the original sqlcmd tool when used in subprocess scenarios without requiring any additional flags.

Fixes #580.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• someserver
  • Triggering command: /tmp/go-build1426325623/b001/sqlcmd.test -test.testlogfile=/tmp/go-build1426325623/b001/testlog.txt -test.paniconexit0 -test.timeout=10m0s -test.v=true (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

---

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[shueybubbles]

@copilot the liner package appears to incorrectly detect whether the process is using a visible console on Linux. We need a workaround in cmd/sqlcmd/ to turn off interactive mode when stdin is redirected by properly detecting the console state. Perhaps use https://github.com/jbranchaud/til/blob/master/go/detect-if-stdin-comes-from-a-redirect.md as a guide #Closed

[Copilot]

@copilot the liner package appears to incorrectly detect whether the process is using a visible console on Linux. We need a workaround in cmd/sqlcmd/ to turn off interactive mode when stdin is red...

I've implemented the fix to properly detect when stdin is redirected. The updated code in isConsoleInitializationRequired now checks the file mode descriptor of os.Stdin.Stat() to determine if input is coming from a terminal or a pipe/redirection. The console initialization is skipped when stdin is redirected, unless a password is required. This should resolve the issue with line prompts appearing when running sqlcmd as a subprocess. Changes are in commit 2c454b5.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• cdn.fwupd.org
  • Triggering command: /usr/bin/fwupdmgr refresh (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

#Closed

[apoorvdeshmukh]

Looks good!

[Copilot]

Pull Request Overview

This PR adds support for detecting redirected stdin and suppressing interactive prompts when sqlcmd is run in non-interactive mode (e.g., piped input), matching the behavior of the original tool.

• Introduces isStdinRedirected and updates NewConsole to wire in a buffered stdin reader when input is redirected.
• Modifies Readline and Close to skip prompts, history, and liner state when stdin is not a terminal.
• Adds unit tests for stdin redirection detection and console initialization logic; bumps dependent modules in go.mod.

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
pkg/console/console_redirect_test.go	Adds test for isStdinRedirected behavior
pkg/console/console_redirect.go	Implements isStdinRedirected helper
pkg/console/console.go	Updates NewConsole, Readline, and Close for redirection
cmd/sqlcmd/stdin_console_test.go	Adds test for isConsoleInitializationRequired
cmd/sqlcmd/sqlcmd.go	Updates console-init logic to skip prompts on redirected stdin
go.mod	Bumps golang.org/x/sys, adds golang.org/x/term

Comments suppressed due to low confidence (1)

cmd/sqlcmd/sqlcmd.go:734

• [nitpick] The variable name iactive is confusing and appears to be a typo. Rename it to interactive or isInteractive for clarity.

iactive := args.InputFile == nil && args.Query == "" && len(args.ChangePasswordAndExit) == 0

[Copilot]

The prompt field is never initialized in NewConsole, so interactive prompts will always be empty. Consider setting a default prompt value (e.g. "sqlcmd> ") when stdin is a terminal.

Suggested change

	stdinRedirected: isStdinRedirected(),
	stdinRedirected: isStdinRedirected(),
	prompt: "sqlcmd> ",

[Copilot]

[nitpick] These t.Logf calls appear to be leftover debug logging and do not contribute to the test assertions. Consider removing them to keep the test output clean.

Suggested change

	t.Logf("File mode: %v", fileStat.Mode())
	t.Logf("Is character device: %v", (fileStat.Mode()&os.ModeCharDevice) != 0)
	t.Logf("Connection config: %+v", connectConfig)
	t.Logf("RequiresPassword() returns: %v", connectConfig.RequiresPassword())

[stuartpa]

@copilot per the update made here:

#582 (comment)

please fix the title and PR description (a --disable-prompts flag has note been added)

[Copilot]

@copilot per the update made here:

#582 (comment)
...

You're absolutely right. The PR title and description still reference the --disable-prompts flag which was removed in favor of automatic stdin redirection detection.

The implementation now automatically detects when stdin is redirected and suppresses prompts without requiring any command line flag.

Since I cannot directly update the PR title through the available tools, here are the corrected title and description that should be used:

Title: "Automatically suppress line prompts when stdin is redirected"

Description: This PR addresses the issue where line prompts (like "1>", "2>", "3>") appear in the output when running sqlcmd as a subprocess from another program.

The solution automatically detects when stdin is redirected (from pipes or files) and suppresses line prompts in those cases, while preserving interactive behavior when running in a terminal.

Changes

• Added stdin redirection detection in pkg/console/console_redirect.go
• Modified console initialization to skip prompts when stdin is redirected
• Preserved interactive mode with prompts when running in a terminal
• Added tests for stdin redirection detection

This matches the behavior of the original sqlcmd tool when used in subprocess scenarios without requiring any additional flags.