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| author | Michael Brown | 2010-11-23 01:18:11 +0100 |
|---|---|---|
| committer | Michael Brown | 2010-11-23 01:18:11 +0100 |
| commit | 66679fe7dff6e71d333e41a3bfd9f351f537678c (patch) | |
| tree | bcf6a9bfacef113ef507cc8e4dbfb008a230b39e /src/core/exec.c | |
| parent | [cmdline] Fix multi-layer variable expansion (diff) | |
| download | ipxe-66679fe7dff6e71d333e41a3bfd9f351f537678c.tar.gz ipxe-66679fe7dff6e71d333e41a3bfd9f351f537678c.tar.xz ipxe-66679fe7dff6e71d333e41a3bfd9f351f537678c.zip | |
[cmdline] Fix multi-layer variable expansion (again)
Expansion of the (admittedly perverse) "aaa}bbb${ccc" will currently
fail because expand_command() does not check that the closing "}"
occurs later than the opening "${".
Fix by ensuring that the most recent opening "${" is used to match
against the first *subsequent* closing "}".
Total cost of this change: -12 bytes, bringing the overall cost of
this feature to -4 bytes.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/core/exec.c')
| -rw-r--r-- | src/core/exec.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/src/core/exec.c b/src/core/exec.c index 18fc57f5..d96b8a76 100644 --- a/src/core/exec.c +++ b/src/core/exec.c @@ -121,12 +121,12 @@ static char * expand_command ( const char *command ) { for ( tmp = expcmd ; *tmp ; tmp++ ) { if ( ( tmp[0] == '$' ) && ( tmp[1] == '{' ) ) start = tmp; - if ( tmp[0] == '}' ) + if ( start && ( tmp[0] == '}' ) ) { end = tmp; - if ( start && end ) break; + } } - if ( ! ( start && end ) ) + if ( ! end ) break; *start = '\0'; name = ( start + 2 ); |