bc: trim banner, use empty interactive prompts (GNU bc compat)

function                                             old     new   delta
bc_vm_run                                            689     684      -5
bc_program_read                                      355     350      -5
bc_read_line                                         307     285     -22
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-32)             Total: -32 bytes
   text	   data	    bss	    dec	    hex	filename
 985409	    485	   7296	 993190	  f27a6	busybox_old
 985265	    485	   7296	 993046	  f2716	busybox_unstripped

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

1 files changed, 19 insertions, 19 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index e543b2b93..cd38bfa42 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -2,9 +2,6 @@
 /*
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  * Copyright (c) 2018 Gavin D. Howard and contributors.
- *
- * ** Automatically generated from https://github.com/gavinhoward/bc **
- * **        Do not edit unless you know what you are doing.         **
  */
 //config:config BC
 //config:       bool "bc (45 kb; 49 kb when combined with dc)"
@@ -97,7 +94,7 @@
 //config:config FEATURE_DC_SMALL
 //config:       bool "Minimal dc implementation (4.2 kb), not using bc code base"
 //config:       depends on DC && !BC
-//config:       default y
+//config:       default n
 //config:
 //config:config FEATURE_DC_LIBM
 //config:       bool "Enable power and exp functions (requires libm)"
@@ -155,11 +152,11 @@
 //usage:       "obase = A\n"
 //usage:
 //usage:#define dc_trivial_usage
-//usage:       "[-eSCRIPT]... [-fFILE]... [FILE]..."
+//usage:       IF_NOT_FEATURE_DC_SMALL("[-x] ")"[-eSCRIPT]... [-fFILE]... [FILE]..."
 //usage:
 //usage:#define dc_full_usage "\n"
 //usage:     "\nTiny RPN calculator. Operations:"
-//usage:     "\n+, -, *, /, %, ~, ^, |,"
+//usage:     "\n+, -, *, /, %, ~, ^," IF_NOT_FEATURE_DC_SMALL(" |,")
 //usage:     "\np - print top of the stack (without popping)"
 //usage:     "\nf - print entire stack"
 //usage:     "\nk - pop the value and set the precision"
@@ -1267,13 +1264,11 @@ static int push_input_byte(BcVec *vec, char c)
         return 0;
 }
 
-static BcStatus bc_read_line(BcVec *vec, const char *prompt)
+static BcStatus bc_read_line(BcVec *vec)
 {
         BcStatus s;
         bool bad_chars;
 
-        if (G_posix) prompt = "";
-
         s = BC_STATUS_SUCCESS;
         do {
                 int c;
@@ -1296,7 +1291,7 @@ static BcStatus bc_read_line(BcVec *vec, const char *prompt)
                 if (G_ttyin) {
                         int n, i;
 #  define line_buf bb_common_bufsiz1
-                        n = read_line_input(G.line_input_state, prompt, line_buf, COMMON_BUFSIZE);
+                        n = read_line_input(G.line_input_state, "", line_buf, COMMON_BUFSIZE);
                         if (n <= 0) { // read errors or EOF, or ^D, or ^C
                                 if (n == 0) // ^C
                                         goto intr;
@@ -1314,8 +1309,6 @@ static BcStatus bc_read_line(BcVec *vec, const char *prompt)
 # endif
 #endif
                 {
-                        if (G_ttyin)
-                                fputs(prompt, stderr);
                         IF_FEATURE_BC_SIGNALS(errno = 0;)
                         do {
                                 c = fgetc(stdin);
@@ -5563,7 +5556,7 @@ static BcStatus bc_program_read(void)
         sv_file = G.prog.file;
         G.prog.file = NULL;
 
-        s = bc_read_line(&buf, "read> ");
+        s = bc_read_line(&buf);
         if (s) goto io_err;
 
         common_parse_init(&parse, BC_PROG_READ);
@@ -6976,8 +6969,6 @@ static void bc_vm_info(void)
 {
         printf("%s "BB_VER"\n"
                 "Copyright (c) 2018 Gavin D. Howard and contributors\n"
-                "Report bugs at: https://github.com/gavinhoward/bc\n"
-                "This is free software with ABSOLUTELY NO WARRANTY\n"
         , applet_name);
 }
 
@@ -7002,7 +6993,6 @@ static void bc_args(char **argv)
         if (getenv("POSIXLY_CORRECT"))
                 option_mask32 |= BC_FLAG_S;
 
-///should be in bc_vm_run() instead??
         if (opts & BC_FLAG_V) {
                 bc_vm_info();
                 exit(0);
@@ -7130,7 +7120,7 @@ static BcStatus bc_vm_stdin(void)
         // with a backslash to the parser. The reason for that is because the parser
         // treats a backslash+newline combo as whitespace, per the bc spec. In that
         // case, and for strings and comments, the parser will expect more stuff.
-        while ((s = bc_read_line(&buf, ">>> ")) == BC_STATUS_SUCCESS) {
+        while ((s = bc_read_line(&buf)) == BC_STATUS_SUCCESS) {
 
                 char *string = buf.v;
 
@@ -7602,8 +7592,18 @@ int dc_main(int argc UNUSED_PARAM, char **argv)
         INIT_G();
         G.sbgn = '[';
         G.send = ']';
-        // TODO: dc (GNU bc 1.07.1) 1.4.1 seems to use default width
-        // 1 char narrower than bc from the same package. Do the same?
+        /*
+         * TODO: dc (GNU bc 1.07.1) 1.4.1 seems to use width
+         * 1 char wider than bc from the same package.
+         * Both default width, and xC_LINE_LENGTH=N are wider:
+         * "DC_LINE_LENGTH=5 dc -e'123456 p'" prints:
+         *      1234\
+         *      56
+         * "echo '123456' | BC_LINE_LENGTH=5 bc" prints:
+         *      123\
+         *      456
+         * Do the same, or it's a bug?
+         */
         bc_vm_init("DC_LINE_LENGTH");
 
         // Run -e'SCRIPT' and -fFILE in order of appearance, then handle FILEs