f8ddbe1cc
Denys Vlasenko
2016-07-25
Subject
ash: fix handling of ${VAR: -2}
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
shell/ash.c +8 -4shell/ash_test/ash-vars/var_bash1a.right +6 -0shell/ash_test/ash-vars/var_bash1a.tests +11 -0
shell/ash.c+8 -4
| @@ -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}, ${VAR:?WORD} |
| + | * constructs. |
| + | */ |
| + | if (!strchr(types, c)) { |
| subtype = VSSUBSTR; | |
| pungetc(); | |
| break; /* "goto do_pungetc" is bigger (!) */ | |
| @@ -11594,7 +11599,6 @@ parsesub: { | |
| flags = VSNUL; | |
| /*FALLTHROUGH*/ | |
| default: { | |
| - | static const char types[] ALIGN1 = "}-+?="; |
| const char *p = strchr(types, c); | |
| if (p == NULL) | |
| goto badsub; | |
shell/ash_test/ash-vars/var_bash1a.right+6 -0
| @@ -0,0 +1,6 @@ | |
| + | parameter 'abcdef' |
| + | varoffset2 'cdef' |
| + | varoffset-2 'ef' |
| + | literal '2' 'cdef' |
| + | literal '-2' 'abcdef' |
| + | literal ' -2' 'ef' |
shell/ash_test/ash-vars/var_bash1a.tests+11 -0
| @@ -0,0 +1,11 @@ | |
| + | parameter=abcdef |
| + | offset=2 |
| + | noffset=-2 |
| + | echo "parameter '${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}'" |