From: Vitaly Magerya <vmagerya@gmail.com>
Date: Wed, 21 Jun 2023 18:48:36 +0000 (+0200)
Subject: [PATCH] Make ginsh evaluate line-by-line in non-interactive mode.
X-Git-Tag: release_1-8-7~4
X-Git-Url: https://ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=4bc2092e2f15a6422774c34c7f8fa4079be67d08

[PATCH] Make ginsh evaluate line-by-line in non-interactive mode.

When used interactively ginsh consumes the input line-by-line, so
if a complete expression is entered it is enough to end the line
to get an evaluated result. In the non-interative mode (i.e. if
the input is not a tty) the input is consumed in blocks, making
it impossible to use ginsh as a subprocess.

This patch makes the non-interactive mode reuse the same line
parsing logic as the interactive mode (without readline), but skips
printing the "> " prompt, preserving the backward compatibility.
---

diff --git a/ginsh/ginsh_lexer.lpp b/ginsh/ginsh_lexer.lpp
index 8692b1ac..5169ecef 100644
--- a/ginsh/ginsh_lexer.lpp
+++ b/ginsh/ginsh_lexer.lpp
@@ -203,8 +203,16 @@ static int ginsh_input(char *buf, int max_size)
 			YY_FATAL_ERROR("input in flex scanner failed");
 		result = n;
 #endif
-	} else if (((result = fread(buf, 1, max_size, yyin)) == 0) && ferror(yyin))
-		YY_FATAL_ERROR("input in flex scanner failed");
+	} else {
+		int c = '*', n;
+		for (n = 0; n < max_size && (c = getc(yyin)) != EOF && c != '\n'; ++n)
+			buf[n] = (char)c;
+		if (c == '\n')
+			buf[n++] = (char)c;
+		if (c == EOF && ferror(yyin))
+			YY_FATAL_ERROR("input in flex scanner failed");
+		result = n;
+	}
 
 	return result;
 }