Hi! On Wed, 24 Apr 2013 15:16:27 +0200, I wrote: > We have a need to pass environment variable assignments containing commas > to user-mode QEMU. The usage information currently says: > > You can use -E and -U options or the QEMU_SET_ENV and > QEMU_UNSET_ENV environment variables to set and unset > environment variables for the target process. > It is possible to provide several variables by separating them > by commas in getsubopt(3) style. Additionally it is possible to > provide the -E and -U options multiple times. > > $ env -i x86_64-linux-user/qemu-x86_64 -E x=y,y=z /usr/bin/printenv > y=z > x=y > > Instead of this, we'd like to see: > > $ env -i x86_64-linux-user/qemu-x86_64 -E x=y,y=z /usr/bin/printenv > x=y,y=z > > Due to the tokenization based on comma in > linux-user/main.c:handle_arg_set_env, there is currently no way to > achieve this -- other than pre-setting environment variables before > running user-mode QEMU, which obviously isn't always desirable/possible > (LD_LIBRARY_PATH, etc.). > > Assuming there is a consensus, how would you like this implemented? > > Is it OK to change the semantics of -E (as well as -U, for symmetry?) to > not handle multiple environment variable assignments (preliminary patch > below), or does that functionality need to be preserved? Something needs > to be done about QEMU_SET_ENV and QEMU_UNSET_ENV then (if anyone is using > these at all, which we can't disprove), as these are not very useful if > they can handle only one environment variable.
That is actually a "regression"/change introduced in commit fc9c54124d134dbd76338a92a91804dab2df8166 (Johannes Schauer CCed, for your information). I'm attaching 0001-linux-user-Document-E-and-U-options.patch to update the documentation for the linux-user QEMU. The bsd-user QEMU has not been changed accordingly, by the way. I'm attaching 0002-linux-user-Use-existing-envlist_parse_set-envlist_pa.patch for some code simplifications. > Or, should we perhaps have a new -env option that causes any later > non-option arguments, that contain an equal sign, to be handled as > environment variable assignments, just like the env command does? > > $ env -i x86_64-linux-user/qemu-x86_64 [some options] -env [more options] > a=b,c d=e,f=a /usr/bin/printenv > a=b,c > d=e,f=a > > I think I might prefer that solution. As it is a new option, it also > won't interfere with anyone's usage/expectations of the current behavior. I'm attaching 0003-linux-user-New-env-option.patch for implementing that. The patches have only been lightly tested; please review. Grüße, Thomas
From eaf53af8d75e001969a658d83d71dd48324c6bcb Mon Sep 17 00:00:00 2001
From: Thomas Schwinge <tho...@codesourcery.com>
Date: Wed, 24 Apr 2013 17:41:58 +0200
Subject: [PATCH 1/3] linux-user: Document -E and -U options.
Document changed behavior introducecd in commit
fc9c54124d134dbd76338a92a91804dab2df8166.
Signed-off-by: Thomas Schwinge <tho...@codesourcery.com>
---
qemu-doc.texi | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff --git qemu-doc.texi qemu-doc.texi
index dfea4d3..3034af4 100644
--- qemu-doc.texi
+++ qemu-doc.texi
@@ -2683,13 +2683,11 @@ Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
Set the x86 stack size in bytes (default=524288)
@item -cpu model
Select CPU model (-cpu help for list and additional feature selection)
-@item -ignore-environment
-Start with an empty environment. Without this option,
-the initial environment is a copy of the caller's environment.
-@item -E @var{var}=@var{value}
-Set environment @var{var} to @var{value}.
-@item -U @var{var}
-Remove @var{var} from the environment.
+@item -E @var{var}=@var{value}[,@var{var2}=@var{value2},...]
+Set environment @var{var} to @var{value}, @var{var2} to @var{value2},
+and so on.
+@item -U @var{var}[,var2,...]
+Remove @var{var}, @var{var2}, and so on from the environment.
@item -B offset
Offset guest address by the specified number of bytes. This is useful when
the address region required by guest applications is reserved on the host.
--
1.7.10.4
From 540f9fa2e9eb197bde3cb91403b6eaaa7d78ac4d Mon Sep 17 00:00:00 2001
From: Thomas Schwinge <tho...@codesourcery.com>
Date: Wed, 24 Apr 2013 17:28:02 +0200
Subject: [PATCH 2/3] linux-user: Use existing
envlist_parse_set/envlist_parse_unset interface.
Signed-off-by: Thomas Schwinge <tho...@codesourcery.com>
---
linux-user/main.c | 18 ++++--------------
util/envlist.c | 4 ++--
2 files changed, 6 insertions(+), 16 deletions(-)
diff --git linux-user/main.c linux-user/main.c
index 4e92a0b..7f81821 100644
--- linux-user/main.c
+++ linux-user/main.c
@@ -3204,26 +3204,16 @@ static void handle_arg_log_filename(const char *arg)
static void handle_arg_set_env(const char *arg)
{
- char *r, *p, *token;
- r = p = strdup(arg);
- while ((token = strsep(&p, ",")) != NULL) {
- if (envlist_setenv(envlist, token) != 0) {
- usage();
- }
+ if (envlist_parse_set(envlist, arg) != 0) {
+ usage();
}
- free(r);
}
static void handle_arg_unset_env(const char *arg)
{
- char *r, *p, *token;
- r = p = strdup(arg);
- while ((token = strsep(&p, ",")) != NULL) {
- if (envlist_unsetenv(envlist, token) != 0) {
- usage();
- }
+ if (envlist_parse_unset(envlist, arg) != 0) {
+ usage();
}
- free(r);
}
static void handle_arg_argv0(const char *arg)
diff --git util/envlist.c util/envlist.c
index ebc06cf..4dbca28 100644
--- util/envlist.c
+++ util/envlist.c
@@ -55,10 +55,10 @@ envlist_free(envlist_t *envlist)
/*
* Parses comma separated list of set/modify environment
- * variable entries and updates given enlist accordingly.
+ * variable entries and updates given envlist accordingly.
*
* For example:
- * envlist_parse(el, "HOME=foo,SHELL=/bin/sh");
+ * envlist_parse_set(el, "HOME=foo,SHELL=/bin/sh");
*
* inserts/sets environment variables HOME and SHELL.
*
--
1.7.10.4
From 71461a2caccfc31287e26ca1edf8ff0053a563f7 Mon Sep 17 00:00:00 2001
From: Thomas Schwinge <tho...@codesourcery.com>
Date: Wed, 24 Apr 2013 17:59:17 +0200
Subject: [PATCH 3/3] linux-user: New -env option.
Signed-off-by: Thomas Schwinge <tho...@codesourcery.com>
---
linux-user/main.c | 29 ++++++++++++++++++++++++++++-
qemu-doc.texi | 6 +++++-
2 files changed, 33 insertions(+), 2 deletions(-)
diff --git linux-user/main.c linux-user/main.c
index 7f81821..7b38b54 100644
--- linux-user/main.c
+++ linux-user/main.c
@@ -38,6 +38,7 @@
char *exec_path;
int singlestep;
+int env_mode;
const char *filename;
const char *argv0;
int gdbstub_port;
@@ -3202,6 +3203,11 @@ static void handle_arg_log_filename(const char *arg)
qemu_set_log_filename(arg);
}
+static void handle_arg_env(const char *arg)
+{
+ env_mode = 1;
+}
+
static void handle_arg_set_env(const char *arg)
{
if (envlist_parse_set(envlist, arg) != 0) {
@@ -3354,6 +3360,8 @@ static const struct qemu_argument arg_table[] = {
"size", "set the stack size to 'size' bytes"},
{"cpu", "QEMU_CPU", true, handle_arg_cpu,
"model", "select CPU (-cpu help for list)"},
+ {"env", "", false, handle_arg_env,
+ "", "enable parsing of the ENV LIST (see below)"},
{"E", "QEMU_SET_ENV", true, handle_arg_set_env,
"var=value", "sets targets environment variable (see below)"},
{"U", "QEMU_UNSET_ENV", true, handle_arg_unset_env,
@@ -3390,7 +3398,7 @@ static void usage(void)
int maxarglen;
int maxenvlen;
- printf("usage: qemu-" TARGET_ARCH " [options] program [arguments...]\n"
+ printf("usage: qemu-" TARGET_ARCH " [options] [env list] program [arguments...]\n"
"Linux CPU emulator (compiled for " TARGET_ARCH " emulation)\n"
"\n"
"Options and associated environment variables:\n"
@@ -3444,9 +3452,11 @@ static void usage(void)
"It is possible to provide several variables by separating them\n"
"by commas in getsubopt(3) style. Additionally it is possible to\n"
"provide the -E and -U options multiple times.\n"
+ "Only with -env it is possible to specify values containing commas.\n"
"The following lines are equivalent:\n"
" -E var1=val2 -E var2=val2 -U LD_PRELOAD -U LD_DEBUG\n"
" -E var1=val2,var2=val2 -U LD_PRELOAD,LD_DEBUG\n"
+ " -env -U LD_PRELOAD,LD_DEBUG var1=val2 var2=val2\n"
" QEMU_SET_ENV=var1=val2,var2=val2 QEMU_UNSET_ENV=LD_PRELOAD,LD_DEBUG\n"
"Note that if you provide several changes to a single variable\n"
"the last change will stay in effect.\n");
@@ -3507,6 +3517,23 @@ static int parse_args(int argc, char **argv)
}
}
+ if (env_mode) {
+ for (;;) {
+ if (optind >= argc) {
+ break;
+ }
+ r = argv[optind];
+ if (strchr(r, '=') == NULL) {
+ break;
+ }
+ if (envlist_setenv(envlist, r) != 0) {
+ usage();
+ }
+
+ optind++;
+ }
+ }
+
if (optind >= argc) {
usage();
}
diff --git qemu-doc.texi qemu-doc.texi
index 3034af4..f48a53e 100644
--- qemu-doc.texi
+++ qemu-doc.texi
@@ -2671,7 +2671,7 @@ qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
@subsection Command line options
@example
-usage: qemu-i386 [-h] [-d] [-L path] [-s size] [-cpu model] [-g port] [-B offset] [-R size] program [arguments...]
+usage: qemu-i386 [-h] [-d] [-L path] [-s size] [-cpu model] [-g port] [-B offset] [-R size] [env list] program [arguments...]
@end example
@table @option
@@ -2683,6 +2683,10 @@ Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
Set the x86 stack size in bytes (default=524288)
@item -cpu model
Select CPU model (-cpu help for list and additional feature selection)
+@item -env
+Enable parsing of the @var{env list}. This means that any
+@var{var}=@var{value} assignments before @var{program} will be added
+to the environment.
@item -E @var{var}=@var{value}[,@var{var2}=@var{value2},...]
Set environment @var{var} to @var{value}, @var{var2} to @var{value2},
and so on.
--
1.7.10.4
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