Import Upstream version 3a1upstream/3a1

1 files changed, 20 insertions, 14 deletions

diff --git a/lineio.scm b/lineio.scm
index 38a7b87..cfffd33 100644
--- a/lineio.scm
+++ b/lineio.scm
@@ -8,7 +8,7 @@
 ;1.  Any copy made of this software must include this copyright notice
 ;in full.
 ;
-;2.  I have made no warrantee or representation that the operation of
+;2.  I have made no warranty or representation that the operation of
 ;this software will be error-free, and I am under no obligation to
 ;provide any services, by way of maintenance, update, or otherwise.
 ;
@@ -17,6 +17,7 @@
 ;promotional, or sales literature without prior written consent in
 ;each case.
 
+(require-if 'compiling 'filename)
 
 ;;@args
 ;;@args port
@@ -63,20 +64,25 @@
 ;;Writes @1 followed by a newline to the given @var{port} and returns
 ;;an unspecified value.  The @var{Port} argument may be omitted, in
 ;;which case it defaults to the value returned by
-;;@code{current-input-port}.@refill
+;;@code{current-input-port}.
 (define (write-line str . port)
   (apply display str port)
   (apply newline port))
 
-;;@args path
-;;@args path port
-;;Displays the contents of the file named by @1 to @var{port}.  The
-;;@var{port} argument may be ommited, in which case it defaults to the
-;;value returned by @code{current-output-port}.
-(define (display-file path . port)
-  (set! port (if (null? port) (current-output-port) (car port)))
-  (call-with-input-file path
-    (lambda (inport)
-      (do ((line (read-line inport) (read-line inport)))
-	  ((eof-object? line))
-	(write-line line port)))))
+;;@args command tmp
+;;@args command
+;;@1 must be a string.  The string @2, if supplied, is a path to use as
+;;a temporary file.  @0 calls @code{system} with @1 as argument,
+;;redirecting stdout to file @2.  @0 returns a string containing the
+;;first line of output from @2.
+(define (system->line command . tmp)
+  (require 'filename)
+  (cond ((null? tmp)
+	 (call-with-tmpnam
+	  (lambda (tmp) (system->line command tmp))))
+	(else
+	 (set! tmp (car tmp))
+	 (and (zero? (system (string-append command " > " tmp)))
+	      (file-exists? tmp)
+	      (let ((line (call-with-input-file tmp read-line)))
+		(if (eof-object? line) "" line))))))