terminal, e.g. when writing to a file. By default, only writes to a terminal
are colored.
+All environment variables starting with 'COLORED_STDERR_PRIVATE_*' are
+internal variables used by the implementation and should not be set manually.
+See the source for details.
+
To set custom colors as pre/post strings you can use the `$''` feature of Bash
and Zsh:
static int initialized;
/* Force hooked writes even when not writing to a tty. Used for tests. */
static int force_write_to_non_tty;
+/* Was ENV_NAME_FDS found and used when init_from_environment() was called?
+ * This is not true if the process set it manually after initialization. */
+static int used_fds_set_by_user;
#include "constants.h"
/* Hook execve() and the other exec*() functions. Some shells use exec*() with
* a custom environment which doesn't necessarily contain our updates to
- * ENV_NAME_FDS. It's also faster to update the environment only when
- * necessary, right before the exec() to pass it to the new process. */
+ * ENV_NAME_PRIVATE_FDS. It's also faster to update the environment only when
+ * necessary, right before the exec(), to pass it to the new program. */
/* int execve(char const *, char * const [], char * const []) */
HOOK_FUNC_DEF3(int, execve, char const *, filename, char * const *, argv, char * const *, env) {
DLSYM_FUNCTION(real_execve, "execve");
- int found = 0;
- size_t index = 0;
-
- /* Count arguments and search for existing ENV_NAME_FDS environment
- * variable. */
+ /* Count environment variables. */
size_t count = 0;
char * const *x = env;
- while (*x) {
- if (!strncmp(*x, ENV_NAME_FDS "=", strlen(ENV_NAME_FDS) + 1)) {
- found = 1;
- index = count;
- }
-
- x++;
+ while (*x++) {
count++;
}
/* Terminating NULL. */
count++;
char *env_copy[count + 1 /* space for our new entry if necessary */];
- memcpy(env_copy, env, count * sizeof(char *));
/* Make sure the information from the environment is loaded. We can't just
* do nothing (like update_environment()) because the caller might pass a
init_from_environment();
}
- char fds_env[strlen(ENV_NAME_FDS) + 1 + update_environment_buffer_size()];
- strcpy(fds_env, ENV_NAME_FDS "=");
- update_environment_buffer(fds_env + strlen(ENV_NAME_FDS) + 1);
+ char fds_env[strlen(ENV_NAME_PRIVATE_FDS)
+ + 1 + update_environment_buffer_size()];
+ strcpy(fds_env, ENV_NAME_PRIVATE_FDS "=");
+ update_environment_buffer(fds_env + strlen(ENV_NAME_PRIVATE_FDS) + 1);
- if (found) {
- env_copy[index] = fds_env;
- } else {
- /* If the process removed ENV_NAME_FDS from the environment, re-add
- * it. */
- env_copy[count-1] = fds_env;
- env_copy[count] = NULL;
+ int found = 0;
+ char **x_copy = env_copy;
+
+ /* Copy the environment manually; allows skipping elements. */
+ x = env;
+ while ((*x_copy = *x)) {
+ /* Remove ENV_NAME_FDS if we've already used its value. The new
+ * program must use the updated list from ENV_NAME_PRIVATE_FDS. */
+ if (used_fds_set_by_user
+ && !strncmp(*x, ENV_NAME_FDS "=", strlen(ENV_NAME_FDS) + 1)) {
+ x++;
+ continue;
+ /* Update ENV_NAME_PRIVATE_FDS. */
+ } else if (!strncmp(*x, ENV_NAME_PRIVATE_FDS "=",
+ strlen(ENV_NAME_PRIVATE_FDS) + 1)) {
+ *x_copy = fds_env;
+ found = 1;
+ }
+
+ x++;
+ x_copy++;
+ }
+ /* The loop "condition" NULL-terminates env_copy. */
+
+ if (!found) {
+ /* If the process removed ENV_NAME_PRIVATE_FDS from the environment,
+ * re-add it. */
+ *x_copy++ = fds_env;
+ *x_copy++ = NULL;
}
return real_execve(filename, argv, env_copy);
#define ENV_NAME_PRE_STRING "COLORED_STDERR_PRE"
#define ENV_NAME_POST_STRING "COLORED_STDERR_POST"
#define ENV_NAME_FORCE_WRITE "COLORED_STDERR_FORCE_WRITE"
+#define ENV_NAME_PRIVATE_FDS "COLORED_STDERR_PRIVATE_FDS"
/* Strings written before/after each matched function. */
#define DEFAULT_PRE_STRING "\033[91m"
/* Load tracked file descriptors from the environment. The environment is used
* to pass the information to child processes.
*
- * ENV_NAME_FDS has the following format: Each descriptor as string followed
- * by a comma; there's a trailing comma. Example: "2,4,". */
+ * ENV_NAME_FDS and ENV_NAME_PRIVATE_FDS have the following format: Each
+ * descriptor as string followed by a comma; there's a trailing comma.
+ * Example: "2,4,". */
static void init_from_environment(void) {
#ifdef DEBUG
debug("init_from_environment()\t\t[%d]\n", getpid());
force_write_to_non_tty = 1;
}
+ /* Prefer user defined list of file descriptors, fall back to file
+ * descriptors passed through the environment from the parent process. */
env = getenv(ENV_NAME_FDS);
+ if (env) {
+ used_fds_set_by_user = 1;
+ } else {
+ env = getenv(ENV_NAME_PRIVATE_FDS);
+ }
if (!env) {
errno = saved_errno;
return;
}
#ifdef DEBUG
debug(" getenv(\"%s\"): \"%s\"\n", ENV_NAME_FDS, env);
+ debug(" getenv(\"%s\"): \"%s\"\n", ENV_NAME_PRIVATE_FDS, env);
#endif
+
/* Environment must be treated read-only. */
char env_copy[strlen(env) + 1];
strcpy(env_copy, env);
return;
}
+ int saved_errno = errno;
+
char env[update_environment_buffer_size()];
env[0] = 0;
update_environment_buffer(env);
#if 0
- debug(" setenv(\"%s\", \"%s\", 1)\n", ENV_NAME_FDS, env);
+ debug(" setenv(\"%s\", \"%s\", 1)\n", ENV_NAME_PRIVATE_FDS, env);
#endif
+ setenv(ENV_NAME_PRIVATE_FDS, env, 1 /* overwrite */);
- setenv(ENV_NAME_FDS, env, 1 /* overwrite */);
+ /* Child processes must use ENV_NAME_PRIVATE_FDS to get the updated list
+ * of tracked file descriptors, not the static list provided by the user
+ * in ENV_NAME_FDS.
+ *
+ * But only remove it if the static list in ENV_NAME_FDS was loaded by
+ * init_from_environment() and merged into ENV_NAME_PRIVATE_FDS. */
+ if (used_fds_set_by_user) {
+ unsetenv(ENV_NAME_FDS);
+ }
+
+ errno = saved_errno;
}
execvp(argv[0], args);
return EXIT_FAILURE;
- } else {
+
+ /* Test handling of COLORED_STDERR_FDS. */
+
+ } else if (!skip--) {
+ /* And the rest. */
close(3);
close(8);
+
+ dup2(2, 5);
+
+ char *args[] = { argv0, NULL };
+ char *envp[] = { ldpreload, "COLORED_STDERR_FDS=5,", NULL };
+
+ execve(argv[0], args, envp);
+ return EXIT_FAILURE;
+ } else if (!skip--) {
+ char *args[] = { argv0, NULL };
+ char *envp[] = { ldpreload, NULL };
+
+ dup2(5, 6);
+ close(5);
+
+ execve(argv[0], args, envp);
+ return EXIT_FAILURE;
+ } else if (!skip--) {
+ close(6);
+
+ char *args[] = { argv0, NULL };
+ setenv("COLORED_STDERR_FDS", "2,", 1);
+
+ execv(argv[0], args);
+ return EXIT_FAILURE;
}
} else if (!skip--) {
puts("argv[0] = |./example_exec|");
puts("environ[0] = |TEST=54|");
- puts("environ[2] = |COLORED_STDERR_FDS=2,|");
+ puts("environ[2] = |COLORED_STDERR_PRIVATE_FDS=2,|");
puts("");
puts("argv[0] = |./example_exec|");
puts("argv[1] = |foo|");
puts("argv[2] = |bar|");
puts("environ[0] = |TEST=55|");
- puts("environ[2] = |COLORED_STDERR_FDS=2,|");
+ puts("environ[2] = |COLORED_STDERR_PRIVATE_FDS=2,|");
puts("");
#endif
}
argv[0] = |./example_exec|
-environ[1] = |COLORED_STDERR_FDS=2,|
+environ[1] = |COLORED_STDERR_PRIVATE_FDS=2,|
CHECKING COLORING.
argv[0] = |./example_exec|
-environ[1] = |COLORED_STDERR_FDS=2,3,|
+environ[1] = |COLORED_STDERR_PRIVATE_FDS=2,3,|
argv[0] = |./example_exec|
-environ[1] = |COLORED_STDERR_FDS=2,3,4,|
+environ[1] = |COLORED_STDERR_PRIVATE_FDS=2,3,4,|
argv[0] = |./example_exec|
-environ[1] = |COLORED_STDERR_FDS=2,3,4,5,|
+environ[1] = |COLORED_STDERR_PRIVATE_FDS=2,3,4,5,|
argv[0] = |./example_exec|
-environ[1] = |COLORED_STDERR_FDS=2,3,4,5,6,|
+environ[1] = |COLORED_STDERR_PRIVATE_FDS=2,3,4,5,6,|
argv[0] = |./example_exec|
-environ[1] = |COLORED_STDERR_FDS=2,3,4,7,|
+environ[1] = |COLORED_STDERR_PRIVATE_FDS=2,3,4,7,|
argv[0] = |./example_exec|
-environ[1] = |COLORED_STDERR_FDS=2,3,8,|
+environ[1] = |COLORED_STDERR_PRIVATE_FDS=2,3,8,|
+
+argv[0] = |./example_exec|
+environ[1] = |COLORED_STDERR_FDS=5,|
+environ[2] = |COLORED_STDERR_PRIVATE_FDS=2,5,|
+
+argv[0] = |./example_exec|
+environ[1] = |COLORED_STDERR_PRIVATE_FDS=6,|
+
+argv[0] = |./example_exec|
+environ[1] = |COLORED_STDERR_PRIVATE_FDS=|
+environ[2] = |COLORED_STDERR_FDS=2,|
CHECKING TRANSPARENCY.
argv[0] = |./example_exec|
-environ[1] = |COLORED_STDERR_FDS=2,|
+environ[1] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
environ[0] = |TEST=42|
-environ[2] = |COLORED_STDERR_FDS=2,|
+environ[2] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
argv[1] = |foo|
argv[2] = |bar|
environ[0] = |TEST=43|
environ[1] = |FOO=|
-environ[3] = |COLORED_STDERR_FDS=2,|
+environ[3] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
environ[0] = |TEST=44|
environ[1] = |FOO=|
-environ[3] = |COLORED_STDERR_FDS=2,|
+environ[3] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
argv[1] = |foo|
argv[2] = |bar|
environ[0] = |TEST=45|
environ[1] = |FOO=|
-environ[3] = |COLORED_STDERR_FDS=2,|
+environ[3] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
environ[0] = |TEST=46|
environ[1] = |FOO=|
-environ[3] = |COLORED_STDERR_FDS=2,|
+environ[3] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
argv[1] = |foo|
argv[2] = |bar|
environ[0] = |TEST=47|
environ[1] = |FOO=|
-environ[3] = |COLORED_STDERR_FDS=2,|
+environ[3] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
-environ[1] = |COLORED_STDERR_FDS=2,|
+environ[1] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
environ[0] = |TEST=48|
-environ[2] = |COLORED_STDERR_FDS=2,|
+environ[2] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
argv[1] = |foo|
argv[2] = |bar|
environ[0] = |TEST=49|
environ[1] = |FOO=|
-environ[3] = |COLORED_STDERR_FDS=2,|
+environ[3] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
environ[0] = |TEST=50|
environ[1] = |FOO=|
-environ[3] = |COLORED_STDERR_FDS=2,|
+environ[3] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
argv[1] = |foo|
argv[2] = |bar|
environ[0] = |TEST=51|
environ[1] = |FOO=|
-environ[3] = |COLORED_STDERR_FDS=2,|
+environ[3] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
environ[0] = |TEST=52|
environ[1] = |FOO=|
-environ[3] = |COLORED_STDERR_FDS=2,|
+environ[3] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
argv[1] = |foo|
argv[2] = |bar|
environ[0] = |TEST=53|
environ[1] = |FOO=|
-environ[3] = |COLORED_STDERR_FDS=2,|
+environ[3] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
environ[0] = |TEST=54|
-environ[2] = |COLORED_STDERR_FDS=2,|
+environ[2] = |COLORED_STDERR_PRIVATE_FDS=2,|
argv[0] = |./example_exec|
argv[1] = |foo|
argv[2] = |bar|
environ[0] = |TEST=55|
-environ[2] = |COLORED_STDERR_FDS=2,|
+environ[2] = |COLORED_STDERR_PRIVATE_FDS=2,|
Done.
LC_ALL=C
unset LANGUAGE
-# Set default COLORED_STDERR_FDS value.
+# Clear user defined variables.
+unset COLORED_STDERR_FDS
+unset COLORED_STDERR_FORCE_WRITE
+# Set default COLORED_STDERR_PRIVATE_FDS value.
fds=2,
(
# Standard setup.
LD_PRELOAD="$library"
- COLORED_STDERR_FDS="$fds"
+ COLORED_STDERR_PRIVATE_FDS="$fds"
export LD_PRELOAD
- export COLORED_STDERR_FDS
+ export COLORED_STDERR_PRIVATE_FDS
# Change pre/post strings for simpler testing.
COLORED_STDERR_PRE='>STDERR>'
test "x$srcdir" = x && srcdir=.
. "$srcdir/lib.sh"
-# Test unexpected values for COLORED_STDERR_FDS environment variable.
+# Test unexpected values for COLORED_STDERR_PRIVATE_FDS environment variable.
# Empty fields.
fds=
fds=-20,-30,2,-1,
test_program example example_environment
test_program_subshell example example_environment
+
+# Test COLORED_STDERR_FDS overwrites COLORED_STDERR_PRIVATE_FDS. Additional
+# tests in example_exec.
+
+fds=
+COLORED_STDERR_FDS=2,
+export COLORED_STDERR_FDS
+test_program example example_environment
+test_program_subshell example example_environment
+
+fds=2,
+COLORED_STDERR_FDS=
+export COLORED_STDERR_FDS
+test_program example example_environment_empty
+test_program_subshell example example_environment_empty
ruderich.org/simon / coloredstderr / coloredstderr.git / commitdiff