shell: more efficient check for EOL in read

function                                             old     new   delta
shell_builtin_read                                  1334    1320     -14

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

2 files changed, 8 insertions, 4 deletions

diff --git a/shell/shell_common.c b/shell/shell_common.c
index 2db8ea3e2..7a0799ed5 100644
--- a/shell/shell_common.c
+++ b/shell/shell_common.c
@@ -65,6 +65,7 @@ shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val),
         int nchars; /* -n NUM */
         char **pp;
         char *buffer;
+        char delim;
         struct termios tty, old_tty;
         const char *retval;
         int bufpos; /* need to be able to hold -1 */
@@ -185,6 +186,7 @@ shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val),
                 end_ms += (unsigned)monotonic_ms();
         buffer = NULL;
         bufpos = 0;
+        delim = opt_d ? *opt_d : '\n';
         do {
                 char c;
                 int timeout;
@@ -238,10 +240,7 @@ shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val),
                                 continue;
                         }
                 }
-                if (opt_d) {
-                        if (c == *opt_d)
-                                break;
-                } else if (c == '\n')
+                if (c == delim) /* '\n' or -d CHAR */
                         break;
 
                 /* $IFS splitting. NOT done if we run "read"
diff --git a/shell/shell_common.h b/shell/shell_common.h
index 1b79bffca..875fd9ea7 100644
--- a/shell/shell_common.h
+++ b/shell/shell_common.h
@@ -34,6 +34,11 @@ enum {
         BUILTIN_READ_SILENT = 1 << 0,
         BUILTIN_READ_RAW    = 1 << 1,
 };
+//TODO? do not provide bashisms if not asked for:
+//#if !ENABLE_HUSH_BASH_COMPAT && !ENABLE_ASH_BASH_COMPAT
+//#define shell_builtin_read(setvar,argv,ifs,read_flags,n,p,t,u,d)
+//      shell_builtin_read(setvar,argv,ifs,read_flags)
+//#endif
 const char* FAST_FUNC
 shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val),
         char       **argv,