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authorDenys Vlasenko2016-07-25 03:56:00 +0200
committerDenys Vlasenko2016-07-25 03:56:00 +0200
commitf8ddbe1ccce9eceaaac28b4b1aa71631fcc56db6 (patch)
tree0782f9ae0ab8bfb74ad8c3fca455f2dcd4de6b33 /shell
parent0fb0045aa9261be1dda49dfdfb95cbc585402a8b (diff)
downloadbusybox-f8ddbe1ccce9eceaaac28b4b1aa71631fcc56db6.zip
busybox-f8ddbe1ccce9eceaaac28b4b1aa71631fcc56db6.tar.gz
ash: fix handling of ${VAR: -2}
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'shell')
-rw-r--r--shell/ash.c12
-rw-r--r--shell/ash_test/ash-vars/var_bash1a.right6
-rwxr-xr-xshell/ash_test/ash-vars/var_bash1a.tests11
3 files changed, 25 insertions, 4 deletions
diff --git a/shell/ash.c b/shell/ash.c
index 4f6376f..496167f 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -6323,6 +6323,8 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
#if ENABLE_ASH_BASH_COMPAT
case VSSUBSTR:
+//TODO: support more general format ${v:EXPR:EXPR},
+// where EXPR follows $(()) rules
loc = str = stackblock() + strloc;
/* Read POS in ${var:POS:LEN} */
pos = atoi(loc); /* number(loc) errors out on "1:4" */
@@ -11577,15 +11579,18 @@ parsesub: {
STPUTC('=', out);
flags = 0;
if (subtype == 0) {
+ static const char types[] ALIGN1 = "}-+?=";
/* ${VAR...} but not $VAR or ${#VAR} */
/* c == first char after VAR */
switch (c) {
case ':':
c = pgetc();
#if ENABLE_ASH_BASH_COMPAT
- if (c == ':' || c == '$' || isdigit(c)) {
-//TODO: support more general format ${v:EXPR:EXPR},
-// where EXPR follows $(()) rules
+ /* This check is only needed to not misinterpret
+ * ${VAR:-WORD}, ${VAR:+WORD}, ${VAR:=WORD}, ${VAR:?WORD}
+ * constructs.
+ */
+ if (!strchr(types, c)) {
subtype = VSSUBSTR;
pungetc();
break; /* "goto do_pungetc" is bigger (!) */
@@ -11594,7 +11599,6 @@ parsesub: {
flags = VSNUL;
/*FALLTHROUGH*/
default: {
- static const char types[] ALIGN1 = "}-+?=";
const char *p = strchr(types, c);
if (p == NULL)
goto badsub;
diff --git a/shell/ash_test/ash-vars/var_bash1a.right b/shell/ash_test/ash-vars/var_bash1a.right
new file mode 100644
index 0000000..1965b5c
--- /dev/null
+++ b/shell/ash_test/ash-vars/var_bash1a.right
@@ -0,0 +1,6 @@
+parameter 'abcdef'
+varoffset2 'cdef'
+varoffset-2 'ef'
+literal '2' 'cdef'
+literal '-2' 'abcdef'
+literal ' -2' 'ef'
diff --git a/shell/ash_test/ash-vars/var_bash1a.tests b/shell/ash_test/ash-vars/var_bash1a.tests
new file mode 100755
index 0000000..551dd9a
--- /dev/null
+++ b/shell/ash_test/ash-vars/var_bash1a.tests
@@ -0,0 +1,11 @@
+parameter=abcdef
+offset=2
+noffset=-2
+echo "parameter '${parameter}'"
+echo "varoffset2 '${parameter:${offset}}'"
+echo "varoffset-2 '${parameter:${noffset}}'"
+echo "literal '2' '${parameter:2}'"
+# This is not inrpreted as ${VAR:POS{:LEN}},
+# but as ${VAR:=WORD} - if VAR is unset or null, substitute WORD
+echo "literal '-2' '${parameter:-2}'"
+echo "literal ' -2' '${parameter: -2}'"