From 0ce5a80601597fe4d1a715a8f70ce8d5ccaa2d86 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Mantas=20Mikul=C4=97nas?= Date: Sun, 13 Jul 2014 18:49:00 +0300 Subject: [PATCH] fileio: quote more shell characters in envfiles Turns out, making strings shell-proof is harder than expected: # machinectl set-hostname "foo|poweroff" && . /etc/machine-info (This could be simplified by quoting *and* escaping all characters, which is harmless in shell but unnecessary.) --- src/shared/fileio.c | 4 ++-- src/shared/util.h | 6 ++++++ 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/src/shared/fileio.c b/src/shared/fileio.c index b0ab780d7..cbb40c237 100644 --- a/src/shared/fileio.c +++ b/src/shared/fileio.c @@ -738,11 +738,11 @@ static void write_env_var(FILE *f, const char *v) { p++; fwrite(v, 1, p-v, f); - if (string_has_cc(p, NULL) || chars_intersect(p, WHITESPACE "\'\"\\`$")) { + if (string_has_cc(p, NULL) || chars_intersect(p, WHITESPACE SHELL_NEED_QUOTES)) { fputc('\"', f); for (; *p; p++) { - if (strchr("\'\"\\`$", *p)) + if (strchr(SHELL_NEED_ESCAPE, *p)) fputc('\\', f); fputc(*p, f); diff --git a/src/shared/util.h b/src/shared/util.h index c5eadc97c..b3187a9ea 100644 --- a/src/shared/util.h +++ b/src/shared/util.h @@ -93,6 +93,12 @@ #define COMMENTS "#;" #define GLOB_CHARS "*?[" +/* What characters are special in the shell? */ +/* must be escaped outside and inside double-quotes */ +#define SHELL_NEED_ESCAPE "\"\\`$" +/* can be escaped or double-quoted */ +#define SHELL_NEED_QUOTES SHELL_NEED_ESCAPE GLOB_CHARS "'()<>|&;" + #define FORMAT_BYTES_MAX 8 #define ANSI_HIGHLIGHT_ON "\x1B[1;39m" -- 2.30.2