From 5f45fd907bf2ef0bbdd87cd991760f98783693d9 Mon Sep 17 00:00:00 2001
From: "Todd C. Miller" <Todd.Miller@sudo.ws>
Date: Thu, 20 Jan 2022 14:05:00 -0700
Subject: [PATCH] Document how commands are passed to the shell for the -i and
 -s options. The concatenation of command and arguments and escaping of
 special characters was not documented. Text adapted from GitHub issue #121
 from Kris Rinzwind

---
 docs/sudo.man.in  | 22 ++++++++++++++++++----
 docs/sudo.mdoc.in | 22 ++++++++++++++++++----
 2 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/docs/sudo.man.in b/docs/sudo.man.in
index 19b5b170f..4c675018a 100644
--- a/docs/sudo.man.in
+++ b/docs/sudo.man.in
@@ -449,10 +449,17 @@ This means that login-specific resource files such as
 or
 \fI.login\fR
 will be read by the shell.
-If a command is specified, it is passed to the shell for execution
-via the shell's
+If a command is specified, it is passed to the shell as a simple
+command using the
 \fB\-c\fR
 option.
+The command and any arguments are concatenated, separated by spaces,
+after escaping each character
+(including white space)
+with a backslash
+(\(oq\e\(cq)
+except for alphanumerics, underscores,
+hyphens, and dollar signs.
 If no command is specified, an interactive shell is executed.
 \fBsudo\fR
 attempts to change to that user's home directory before running the
@@ -624,10 +631,17 @@ Run the shell specified by the
 \fRSHELL\fR
 environment variable if it is set or the shell specified by the
 invoking user's password database entry.
-If a command is specified, it is passed to the shell for execution
-via the shell's
+If a command is specified, it is passed to the shell as a simple
+command using the
 \fB\-c\fR
 option.
+The command and any arguments are concatenated, separated by spaces,
+after escaping each character
+(including white space)
+with a backslash
+(\(oq\e\(cq)
+except for alphanumerics, underscores,
+hyphens, and dollar signs.
 If no command is specified, an interactive shell is executed.
 Note that most shells behave differently when a command is specified
 as compared to an interactive session; consult the shell's manual
diff --git a/docs/sudo.mdoc.in b/docs/sudo.mdoc.in
index 9c373615d..a930549ed 100644
--- a/docs/sudo.mdoc.in
+++ b/docs/sudo.mdoc.in
@@ -426,10 +426,17 @@ This means that login-specific resource files such as
 or
 .Pa .login
 will be read by the shell.
-If a command is specified, it is passed to the shell for execution
-via the shell's
+If a command is specified, it is passed to the shell as a simple
+command using the
 .Fl c
 option.
+The command and any arguments are concatenated, separated by spaces,
+after escaping each character
+.Pq including white space
+with a backslash
+.Pq Ql \e
+except for alphanumerics, underscores,
+hyphens, and dollar signs.
 If no command is specified, an interactive shell is executed.
 .Nm
 attempts to change to that user's home directory before running the
@@ -582,10 +589,17 @@ Run the shell specified by the
 .Ev SHELL
 environment variable if it is set or the shell specified by the
 invoking user's password database entry.
-If a command is specified, it is passed to the shell for execution
-via the shell's
+If a command is specified, it is passed to the shell as a simple
+command using the
 .Fl c
 option.
+The command and any arguments are concatenated, separated by spaces,
+after escaping each character
+.Pq including white space
+with a backslash
+.Pq Ql \e
+except for alphanumerics, underscores,
+hyphens, and dollar signs.
 If no command is specified, an interactive shell is executed.
 Note that most shells behave differently when a command is specified
 as compared to an interactive session; consult the shell's manual