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author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-05-28 18:21:46 +0900 |
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committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-05-29 03:31:19 +0900 |
commit | 2fd5b09c201e20ab87299efd6a25f0bfc546e7c9 (patch) | |
tree | 712cb918bbc6c7f58314e03330ea51bec6612905 | |
parent | e298f3b49def8e67c2466bef8aed355462bfa7f1 (diff) | |
download | linux-2fd5b09c201e20ab87299efd6a25f0bfc546e7c9.tar.gz linux-2fd5b09c201e20ab87299efd6a25f0bfc546e7c9.tar.bz2 linux-2fd5b09c201e20ab87299efd6a25f0bfc546e7c9.zip |
kconfig: add 'shell' built-in function
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@socionext.com>
-rw-r--r-- | scripts/kconfig/preprocess.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c index f32a496626da..528be594e1d0 100644 --- a/scripts/kconfig/preprocess.c +++ b/scripts/kconfig/preprocess.c @@ -106,8 +106,49 @@ struct function { char *(*func)(int argc, char *argv[]); }; +static char *do_shell(int argc, char *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 Function */ + { "shell", 1, 1, do_shell }, }; #define FUNCTION_MAX_ARGS 16 |