This accepts a single command to execute. It returns the standard output from it. [Example code] config HELLO string default "$(shell,echo hello world)" config Y def_bool $(shell,echo y) [Result] $ make -s alldefconfig && tail -n 2 .config CONFIG_HELLO="hello world" CONFIG_Y=y Caveat: Like environments, functions are expanded in the lexer. You cannot pass symbols to function arguments. This is a limitation to simplify the implementation. I want to avoid the dynamic function evaluation, which would introduce much more complexity. Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> --- Changes in v4: - Accept only one argument to simplify the implementation Changes in v3: None Changes in v2: None scripts/kconfig/preprocess.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c index 5be28ec..d8c5f60 100644 --- a/scripts/kconfig/preprocess.c +++ b/scripts/kconfig/preprocess.c @@ -104,8 +104,49 @@ struct function { char *(*func)(int argc, char *argv[], int old_argc, char *old_argv[]); }; +static char *do_shell(int argc, char *argv[], int old_argc, char *old_argv[]) +{ + FILE *p; + char buf[256]; + char *cmd; + size_t nread; + int i; + + cmd = argv[0]; + + p = popen(cmd, "r"); + if (!p) { + perror(cmd); + exit(1); + } + + nread = fread(buf, 1, sizeof(buf), p); + if (nread == sizeof(buf)) + nread--; + + /* remove trailing new lines */ + while (buf[nread - 1] == '\n') + nread--; + + buf[nread] = 0; + + /* replace a new line with a space */ + for (i = 0; i < nread; i++) { + if (buf[i] == '\n') + buf[i] = ' '; + } + + if (pclose(p) == -1) { + perror(cmd); + exit(1); + } + + return xstrdup(buf); +} + static const struct function function_table[] = { /* Name MIN MAX EXP? Function */ + { "shell", 1, 1, true, do_shell }, }; #define FUNCTION_MAX_ARGS 16 -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html