\nA customer was having trouble manipulating the stdin stream\nthat was given to a process.\n<\/p>\n
\n\nHow do you simulate sending Ctrl+Z to a hidden console process\nprogrammatically?\n<\/p>\n
\nI am using
RedirectStandardInput<\/code>\nand want to send the console a Ctrl+Z.\nI’ve tried sending ASCII code 26, but that doesn’t work.\nGenerateConsoleCtrlEvent<\/code> supports Ctrl+C\nand\nCtrl+Break but not Ctrl+Z.\n<\/p>\n\nHere’s what I’m doing, but it doesn’t work:\n<\/p>\n
\nProcessStartInfo info = new ProcessStartInfo(@\"...\");\ninfo.CreateNoWindow = true;\ninfo.RedirectStandardError = true;\ninfo.RedirectStandardOutput = true;\ninfo.RedirectStandardInput = true;\ninfo.UseShellExecute = false;\nProcess p = Process.Start(info);\n\/\/ 0x1A is ASCII code of Ctrl+Z but it does not work\np.StandardInput.WriteLine(\"\\x1A\");\n<\/pre>\n<\/blockquote>\n\nThe customer was kind enough to do more than simply ask the\nquestion.\nThe customer set up the scenario and even provided a code fragment\nthat illustrates the problem.\nWhich is good, because the original question was the wrong question<\/i>.\n<\/p>\n
\nThe customer asked about simulating typing Ctrl+Z to a console,\nbut what they actually doing was sending a character to stdin;\nthey weren’t sending it to a console.\nIn fact, the way they created the process,\nthere is no console at all<\/i>.\n<\/p>\n
\nThe customer confused stdin with consoles.\nIt’s true that Ctrl+Z is the convention used by console windows\nto indicate that stdin should be closed.\nBut that is hardly any consolation when you took control of stdin yourself\nand are not using a console window to manage it.\n<\/p>\n
\nIt’s like saying,\n“Normally, when I want somebody to take my order,\nI pull into a parking space and\n\nturn on my headlights<\/a>,\nand somebody will come out.\nBut I can’t get it to work.”\n<\/p>\n
\n— Um, that’s because you pulled into your own driveway.<\/i>\n<\/p>\n
\nCtrl+Z is a convention used by console windows to indicate that\nstdin should be closed, but if you said “I am going to manage stdin myself,”\nthen you aren’t using a console window,\nand that convention carries no weight.\nIf you write a Ctrl+Z to the process’s stdin, it will simply read a Ctrl+Z.\nBut since you are managing stdin yourself,\nyou can do it yourself:\nJust take the stream you set as the process’s stdin and\n\nclose it<\/a>.\n<\/p>\n
\nExercise<\/b>:\nPerhaps you can answer this related question from a different customer:\n<\/p>\n
\n\nI am trying to send a Ctrl+C (SIGINT) to a process.\n<\/p>\n
\nCurrentProcess = new Process();\nCurrentProcess.StartInfo.FileName = \"foo.exe\";\nCurrentProcess.StartInfo.UseShellExecute = false;\nCurrentProcess.StartInfo.RedirectStandardInput = true;\nStandardInputWriter = CurrentProcess.StandardInput;\nchar c = '\\u0003';\nStandardInputWriter.Write(c);\nStandardInputWriter.Flush();\nStandardInputWriter.Close();\n<\/pre>\n\nIf I launch the process from a command prompt and type\nCtrl+C, it flushes its output and terminates,\nbut when I start it from within my application and send\nit a Ctrl+C via the code above,\nthe process is still running.\nHow do I send a Ctrl+C to a process?\n<\/p>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"
A customer was having trouble manipulating the stdin stream that was given to a process. How do you simulate sending Ctrl+Z to a hidden console process programmatically? I am using RedirectStandardInput and want to send the console a Ctrl+Z. I’ve tried sending ASCII code 26, but that doesn’t work. GenerateConsoleCtrlEvent supports Ctrl+C and Ctrl+Break but […]<\/p>\n","protected":false},"author":1069,"featured_media":111744,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[25],"class_list":["post-10243","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-code"],"acf":[],"blog_post_summary":"
A customer was having trouble manipulating the stdin stream that was given to a process. How do you simulate sending Ctrl+Z to a hidden console process programmatically? I am using RedirectStandardInput and want to send the console a Ctrl+Z. I’ve tried sending ASCII code 26, but that doesn’t work. GenerateConsoleCtrlEvent supports Ctrl+C and Ctrl+Break but […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/10243","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/users\/1069"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/comments?post=10243"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/10243\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media\/111744"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media?parent=10243"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=10243"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=10243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}