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| author | Denys Vlasenko <vda.linux@googlemail.com> | 2017-07-06 19:48:20 +0200 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2017-07-06 19:48:20 +0200 |
| commit | 5dad7bdc3bdad8e9934d45301d5a8c51e843cd7b (patch) | |
| tree | db493d6ca6cabddcfe3e9a58f33ee712bd1584d4 /shell/hush.c | |
| parent | 3234045d07c3fb2a9ef8afd02f821158317adbd3 (diff) | |
| download | busybox-5dad7bdc3bdad8e9934d45301d5a8c51e843cd7b.tar.gz | |
hush: implement negative start in the ${v: -n[:m]} idiom
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'shell/hush.c')
| -rw-r--r-- | shell/hush.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/shell/hush.c b/shell/hush.c index 64b33cf1c..f6b50dec6 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -5619,8 +5619,12 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha goto arith_err; debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len); if (len >= 0) { /* bash compat: len < 0 is illegal */ - if (beg < 0) /* bash compat */ - beg = 0; + if (beg < 0) { + /* negative beg counts from the end */ + beg = (arith_t)strlen(val) + beg; + if (beg < 0) /* ${v: -999999} is "" */ + beg = len = 0; + } debug_printf_varexp("from val:'%s'\n", val); if (len == 0 || !val || beg >= strlen(val)) { arith_err: |