More work to os/execute.

Use environ when eflag not given. Also try to escape windows
command line strings correctly.
This commit is contained in:
Calvin Rose 2019-05-31 13:43:38 -04:00
parent 2acc81d1c5
commit c43aaf8986
1 changed files with 120 additions and 29 deletions

View File

@ -49,6 +49,7 @@
#include <dirent.h>
#include <sys/types.h>
#include <sys/wait.h>
extern char **environ;
#endif
/* For macos */
@ -167,7 +168,11 @@ static char **os_execute_env(int32_t argc, const Janet *argv) {
/* Free memory from os_execute */
static void os_execute_cleanup(char **envp, const char **child_argv) {
#ifdef JANET_WINDOWS
(void) child_argv;
#else
free((void *)child_argv);
#endif
if (NULL != envp) {
char **envitem = envp;
while (*envitem != NULL) {
@ -178,11 +183,124 @@ static void os_execute_cleanup(char **envp, const char **child_argv) {
free(envp);
}
#ifdef JANET_WINDOWS
/* Windows processes created via CreateProcess get only one command line argument string, and
* must parse this themselves. Each processes is free to do this however they like, but the
* standard parsing method is CommandLineToArgvW. We need to properly escape arguments into
* a single string of this format. Returns a buffer that can be cast into a c string. */
static JanetBuffer *os_exec_escape(JanetView args) {
JanetBuffer *b = janet_buffer(0);
for (int32_t i = 0; i < args.len; i++) {
const char *arg = janet_getcstring(args.items, i);
/* Push leading space if not first */
if (i) janet_buffer_push_u8(b, ' ');
/* Find first special character */
const char *first_spec = arg;
while (*first_spec) {
switch (*first_spec) {
case ' ':
case '\t':
case '\v':
case '\n':
case '"':
goto found;
case '\0':
janet_panic("embedded 0 not allowed in command line string");
default:
first_spec++;
break;
}
}
found:
/* Check if needs escape */
if (*first_spec == '\0') {
/* No escape needed */
janet_buffer_push_cstring(b, arg);
} else {
/* Escape */
janet_buffer_push_u8(b, '"');
for (const char *c = arg; ; c++) {
unsigned numBackSlashes = 0;
while (*c == '\\') {
c++;
numBackSlashes++;
}
if (*c == '"') {
/* Escape all backslashes and double quote mark */
int32_t n = 2 * numBackSlashes + 1;
janet_buffer_extra(b, n + 1);
memset(b->data + b->count, '\\', n);
b->count += n;
janet_buffer_push_u8(b, '"');
} else if (*c) {
/* Don't escape backslashes. */
int32_t n = numBackSlashes;
janet_buffer_extra(b, n + 1);
memset(b->data + b->count, '\\', n);
b->count += n;
janet_buffer_push_u8(b, *c);
} else {
/* we finished Escape all backslashes */
int32_t n = 2 * numBackSlashes;
janet_buffer_extra(b, n + 1);
memset(b->data + b->count, '\\', n);
b->count += n;
break;
}
}
janet_buffer_push_u8(b, '"');
}
}
janet_buffer_push_u8(b, 0);
return b;
}
#endif
static Janet os_execute(int32_t argc, Janet *argv) {
janet_arity(argc, 1, 3);
/* Get flags */
int flags = os_execute_flags(argc, argv);
/* Get environment */
char **envp = os_execute_env(argc, argv);
/* Get arguments */
JanetView exargs = janet_getindexed(argv, 0);
if (exargs.len < 1) {
janet_panic("expected at least 1 command line argument");
}
#ifdef JANET_WINDOWS
JanetBuffer *buf = os_exec_escape(exargs);
if (buf->count > 1025) {
janet_panic("command line string too long");
}
const char *path = (const char *) janet_unwrap_string(exargs.items[0]);
char *cargv[2] = {(char *) buf->data, NULL};
/* Use _spawn family of functions. */
/* Windows docs say do this before any spawns. */
_flushall();
if (flags & (JANET_OS_EFLAG_P | JANET_OS_EFLAG_E)) {
status = (int) _spawnvpe(_P_WAIT, path, cargv, envp);
} else if (flags & JANET_OS_EFLAG_P) {
status = (int) _spawnvp(_P_WAIT, path, cargv);
} else if (flags & JANET_OS_EFLAG_E) {
status = (int) _spawnve(_P_WAIT, path, cargv, envp);
} else {
status = (int) _spawnv(_P_WAIT, path, cargv);
}
os_execute_cleanup(envp, NULL);
return janet_wrap_integer(status);
#else
const char **child_argv = malloc(sizeof(char *) * (exargs.len + 1));
int status = 0;
if (NULL == child_argv) {
@ -192,47 +310,20 @@ static Janet os_execute(int32_t argc, Janet *argv) {
child_argv[i] = janet_getcstring(exargs.items, i);
}
child_argv[exargs.len] = NULL;
/* Get flags */
int flags = os_execute_flags(argc, argv);
/* Get environment */
char **envp = os_execute_env(argc, argv);
/* Coerce to form that works for spawn. I'm fairly confident no implementation
* of posix_spawn would modify the argv array passed in. */
char *const *cargv = (char *const *)child_argv;
#ifdef JANET_WINDOWS
/* Use _spawn family of functions. */
/* Windows docs say do this before any spawns. */
_flushall();
if (flags & (JANET_OS_EFLAG_P | JANET_OS_EFLAG_E)) {
status = (int) _spawnvpe(_P_WAIT, child_argv[0], cargv, envp);
} else if (flags & JANET_OS_EFLAG_P) {
status = (int) _spawnvp(_P_WAIT, child_argv[0], cargv);
} else if (flags & JANET_OS_EFLAG_E) {
status = (int) _spawnve(_P_WAIT, child_argv[0], cargv, envp);
} else {
status = (int) _spawnv(_P_WAIT, child_argv[0], cargv);
}
os_execute_cleanup(envp, child_argv);
return janet_wrap_integer(status);
#else
/* Use posix_spawn to spawn new process */
pid_t pid;
if (flags & JANET_OS_EFLAG_P) {
status = posix_spawnp(&pid,
child_argv[0], NULL, NULL, cargv,
(flags & JANET_OS_EFLAG_E) ? envp : NULL);
(flags & JANET_OS_EFLAG_E) ? envp : environ);
} else {
status = posix_spawn(&pid,
child_argv[0], NULL, NULL, cargv,
(flags & JANET_OS_EFLAG_E) ? envp : NULL);
(flags & JANET_OS_EFLAG_E) ? envp : environ);
}
/* Wait for child */