shell: move varcmp() to shell_common.h and use it in hush

function                                             old     new   delta
unset_local_var                                        -     112    +112
findvar                                               31      35      +4
set_vars_and_save_old                                144     141      -3
helper_export_local                                  235     230      -5
set_local_var                                        425     416      -9
handle_changed_special_names                          38      27     -11
builtin_unset                                        154     141     -13
builtin_getopts                                      404     391     -13
get_local_var_value                                  281     260     -21
get_ptr_to_local_var                                  71      45     -26
unset_local_var_len                                  139       -    -139
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 1/8 up/down: 116/-240)         Total: -124 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/shell/shell_common.c b/shell/shell_common.c
index 1eca101b9..e5c2cefb3 100644
--- a/shell/shell_common.c
+++ b/shell/shell_common.c
@@ -22,6 +22,25 @@
 const char defifsvar[] ALIGN1 = "IFS= \t\n";
 const char defoptindvar[] ALIGN1 = "OPTIND=1";
 
+/* Compare two strings up to the first '=' or '\0'. */
+int FAST_FUNC varcmp(const char *p, const char *q)
+{
+        int c, d;
+
+        while ((c = *p) == (d = *q)) {
+                if (c == '\0' || c == '=')
+                        goto out;
+                p++;
+                q++;
+        }
+        if (c == '=')
+                c = '\0';
+        if (d == '=')
+                d = '\0';
+ out:
+        return c - d;
+}
+
 /* read builtin */
 
 /* Needs to be interruptible: shell must handle traps and shell-special signals