diff options
| author | Michael Brown | 2010-11-22 22:31:00 +0100 |
|---|---|---|
| committer | Michael Brown | 2010-11-22 22:34:35 +0100 |
| commit | c1327e43ab4c9281651e8505a2149a96c11371b4 (patch) | |
| tree | 9aba6931e639102dd580d198ea4047790a15400d /src/core/exec.c | |
| parent | [settings] Allow "set" command to take an empty value (diff) | |
| download | ipxe-c1327e43ab4c9281651e8505a2149a96c11371b4.tar.gz ipxe-c1327e43ab4c9281651e8505a2149a96c11371b4.tar.xz ipxe-c1327e43ab4c9281651e8505a2149a96c11371b4.zip | |
[cmdline] Fix multi-layer variable expansion
Expansion of ${${foo}} will currently fail, because the first
opening "${" will be incorrectly matched against the first closing
"}", leading to an attempt to expand the variable "${foo".
Fix by ensuring that the most recent opening "${" is used to match
against the first closing "}".
Total cost: 8 bytes. :)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/core/exec.c')
| -rw-r--r-- | src/core/exec.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/src/core/exec.c b/src/core/exec.c index f65a4647..18fc57f5 100644 --- a/src/core/exec.c +++ b/src/core/exec.c @@ -115,17 +115,21 @@ static char * expand_command ( const char *command ) { head = expcmd; - /* Locate opener */ - start = strstr ( expcmd, "${" ); - if ( ! start ) + /* Locate setting to be expanded */ + start = NULL; + end = NULL; + for ( tmp = expcmd ; *tmp ; tmp++ ) { + if ( ( tmp[0] == '$' ) && ( tmp[1] == '{' ) ) + start = tmp; + if ( tmp[0] == '}' ) + end = tmp; + if ( start && end ) + break; + } + if ( ! ( start && end ) ) break; *start = '\0'; name = ( start + 2 ); - - /* Locate closer */ - end = strstr ( name, "}" ); - if ( ! end ) - break; *end = '\0'; tail = ( end + 1 ); |