[PATCH 1/3] parse_shell_args.c: shell-like argument list parser

From: Kirill A. Shutemov
Date: Thu Feb 05 2009 - 15:44:22 EST

It's implementation of argument list parser using shell rules.

Signed-off-by: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
---
include/linux/kernel.h | 2 +
lib/Makefile | 2 +-
lib/parse_shell_args.c | 238 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 241 insertions(+), 1 deletions(-)
create mode 100644 lib/parse_shell_args.c

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 343df9e..6095a84 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -208,6 +208,8 @@ extern int func_ptr_is_kernel_text(void *ptr);
struct pid;
extern struct pid *session_of_pgrp(struct pid *pgrp);

+extern int parse_shell_args(const char *in, char *out, size_t out_size);
+
/*
* FW_BUG
* Add this to a message where you are sure the firmware is buggy or behaves
diff --git a/lib/Makefile b/lib/Makefile
index 32b0e64..3aaf2f3 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -20,7 +20,7 @@ lib-y += kobject.o kref.o klist.o

obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
- string_helpers.o
+ string_helpers.o parse_shell_args.o

ifeq ($(CONFIG_DEBUG_KOBJECT),y)
CFLAGS_kobject.o += -DDEBUG
diff --git a/lib/parse_shell_args.c b/lib/parse_shell_args.c
new file mode 100644
index 0000000..2b32cab
--- /dev/null
+++ b/lib/parse_shell_args.c
@@ -0,0 +1,238 @@
+/*
+ * lib/parse_shell_args.c
+ *
+ * Copiright (C) 2009 Kirill A. Shutemov
+ *
+ * Shell-like argument list parser
+ */
+
+#ifdef __KERNEL__
+#include <linux/module.h>
+#include <linux/types.h>
+#else
+#include <sys/types.h>
+#endif
+
+#define S_START 0
+#define S_DONE 1
+#define S_NORMAL 2
+#define S_QUOTE 3
+#define S_DQUOTE 4
+
+/**
+ * parse_shell_args - parse shell-like argument list
+ *
+ * @in: null-terminated input string
+ * @out: output buffer
+ * @out_size: output buffer size in byte
+ *
+ * Returns number of arguments or 0 on error.
+ * Parsed arguments store in @out separated by '\0'
+ */
+int parse_shell_args(const char *in, char *out, size_t out_size)
+{
+ int state = S_START;
+ const char *in_p = in;
+ char *out_p = out;
+ int argc = 0;
+ int escape = 0;
+
+ while (state != S_DONE) {
+ if (out_p - out >= out_size)
+ return 0;
+
+ if (escape) {
+ *out_p++ = *in_p++;
+ escape = 0;
+ continue;
+ }
+
+ switch (state) {
+ case S_START:
+ switch (*in_p) {
+ case '\n':
+ case '\0':
+ state = S_DONE;
+ *out_p = '\0';
+ break;
+ case ' ':
+ case '\t':
+ in_p++;
+ break;
+ case '\'':
+ state = S_QUOTE;
+ in_p++;
+ argc++;
+ break;
+ case '"':
+ state = S_DQUOTE;
+ in_p++;
+ argc++;
+ break;
+ default:
+ state = S_NORMAL;
+ argc++;
+ break;
+ }
+ break;
+
+ case S_NORMAL:
+ switch (*in_p) {
+ case '\n':
+ case '\0':
+ state = S_DONE;
+ *out_p = '\0';
+ break;
+ case ' ':
+ case '\t':
+ state = S_START;
+ *out_p++ = '\0';
+ break;
+ case '\'':
+ state = S_QUOTE;
+ in_p++;
+ break;
+ case '\"':
+ state = S_DQUOTE;
+ in_p++;
+ break;
+ case '\\':
+ in_p++;
+ escape = 1;
+ break;
+ default:
+ *out_p++ = *in_p++;
+ break;
+ }
+ break;
+
+ case S_QUOTE:
+ switch (*in_p) {
+ case '\'':
+ state = S_NORMAL;
+ in_p++;
+ break;
+ case '\n':
+ case '\0':
+ return 0;
+ break;
+ default:
+ *out_p++ = *in_p++;
+ break;
+ }
+ break;
+ case S_DQUOTE:
+ switch (*in_p) {
+ case '\"':
+ state = S_NORMAL;
+ in_p++;
+ break;
+ case '\n':
+ case '\0':
+ return 0;
+ break;
+ case '\\':
+ if (*(in_p+1) == '$' ||
+ *(in_p+1) == '`' ||
+ *(in_p+1) == '"' ||
+ *(in_p+1) == '\\' ||
+ *(in_p+1) == '\n') {
+ in_p++;
+ escape = 1;
+ } else
+ *out_p++ = *in_p++;
+ break;
+ default:
+ *out_p++ = *in_p++;
+ break;
+ }
+ break;
+ default:
+ return 0;
+ break;
+ }
+ }
+
+ return argc;
+}
+
+#ifdef __KERNEL__
+EXPORT_SYMBOL(parse_shell_args);
+#else
+/* Unit tests */
+
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+
+static void test_parse(const char *in, const char *expected_out, int expected_argc)
+{
+ char out[PATH_MAX];
+ char *out_p = out;
+ int i;
+ int argc;
+
+ argc = parse_shell_args(in, out, PATH_MAX);
+
+ if (argc != expected_argc) {
+ printf("%s: wrong argc: %d, but expected %d\n", in, argc, expected_argc);
+ return;
+ }
+
+ for(i=0; i < argc; i++) {
+ int len;
+
+ if (strcmp(expected_out, out_p)) {
+ printf("%s: %s, but expected %s\n", in , out_p, expected_out);
+ return;
+ }
+
+ len = strlen(expected_out);
+ expected_out += len + 1;
+ out_p += len + 1;
+ }
+
+ printf("%s:\tOK\n", in);
+}
+
+int main(void)
+{
+ test_parse("", "", 0);
+
+ test_parse("/bin/ls", "/bin/ls", 1);
+ test_parse("/bin\\ ls", "/bin ls", 1);
+ test_parse("/bin/ls\n", "/bin/ls", 1);
+ test_parse("/bin/ls\\\n", "/bin/ls\n", 1);
+ test_parse(" /bin/ls", "/bin/ls", 1);
+ test_parse("\t/bin/ls", "/bin/ls", 1);
+ test_parse("/bin/ls ", "/bin/ls", 1);
+ test_parse("/bin/ls\t", "/bin/ls", 1);
+ test_parse("\\'/bin/ls", "\'/bin/ls", 1);
+ test_parse("/bin\\'/ls", "/bin\'/ls", 1);
+ test_parse("/bin'/ls", "", 0);
+ test_parse("/bin\"/ls", "", 0);
+
+ test_parse("'/bin/ls'", "/bin/ls", 1);
+ test_parse("'/bin ls'", "/bin ls", 1);
+ test_parse("'/bin\tls'", "/bin\tls", 1);
+ test_parse("'/bin''/ls'", "/bin/ls", 1);
+ test_parse("/bin'/ls'", "/bin/ls", 1);
+ test_parse("'/bin'/ls", "/bin/ls", 1);
+ test_parse("'/bin \t\"%$#@/ls'", "/bin \t\"%$#@/ls", 1);
+
+ test_parse("\"/bin/ls\"", "/bin/ls", 1);
+ test_parse("\"/bin\"\"/ls\"", "/bin/ls", 1);
+ test_parse("/bin\"/ls\"", "/bin/ls", 1);
+ test_parse("\"/bin\"/ls", "/bin/ls", 1);
+ test_parse("\"\\$\\`\\\"\\\\\\\n\\\\!\\@\\#\\%\\a\"", "$`\"\\\n\\!\\@\\#\\%\\a", 1);
+ test_parse("\"/bin/ls\\\"", "", 0);
+
+ test_parse("/bin/ls -a", "/bin/ls\0-a", 2);
+ test_parse("/bin/ls\t-a", "/bin/ls\0-a", 2);
+ test_parse("/bin/ls \t \t-a", "/bin/ls\0-a", 2);
+ test_parse("/bin/ls -a -l", "/bin/ls\0-a\0-l", 3);
+ test_parse("/bin/ls '-a -l'", "/bin/ls\0-a -l", 2);
+
+ return 0;
+}
+#endif
--
1.6.0.2.GIT

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