Test driver (and much-needed fixes) to fgets().

[pdclib] / functions / stdio / fgets.c

diff --git a/functions/stdio/fgets.c b/functions/stdio/fgets.c
index 203d3ff0306643de6527de273556f155266a36a1..1afd79f6ed7ed50426dadd32414d3a5c1f851df3 100644 (file)
--- a/functions/stdio/fgets.c
+++ b/functions/stdio/fgets.c
@@ -1,6 +1,6 @@
 /* $Id$ */
 
-/* fgets( char *, int, FILE * );
+/* fgets( char *, int, FILE * )
 
    This file is part of the Public Domain C Library (PDCLib).
    Permission is granted to use, modify, and / or redistribute at will.
@@ -10,21 +10,81 @@
 
 #ifndef REGTEST
 
-char * fgets( char * _PDCLIB_restrict s, int n, struct _PDCLIB_file_t * _PDCLIB_restrict stream )
+#define _PDCLIB_GLUE_H _PDCLIB_GLUE_H
+#include <_PDCLIB_glue.h>
+
+char * fgets( char * _PDCLIB_restrict s, int size, struct _PDCLIB_file_t * _PDCLIB_restrict stream )
 {
-    /* TODO: Implement. */
-    return NULL;
+    if ( size == 0 )
+    {
+        return NULL;
+    }
+    if ( size == 1 )
+    {
+        *s = '\0';
+        return s;
+    }
+    if ( _PDCLIB_prepread( stream ) == EOF )
+    {
+        return NULL;
+    }
+    char * dest = s;
+    while ( ( ( *dest++ = stream->buffer[stream->bufidx++] ) != '\n' ) && --size > 0 )
+    {
+        if ( stream->bufidx == stream->bufend )
+        {
+            if ( _PDCLIB_fillbuffer( stream ) == EOF )
+            {
+                /* In case of error / EOF before a character is read, this
+                   will lead to a \0 be written anyway. Since the results
+                   are "indeterminate" by definition, this does not hurt.
+                */
+                break;
+            }
+        }
+    }
+    *dest = '\0';
+    return ( dest == s ) ? NULL : s;
 }
 
 #endif
 
 #ifdef TEST
 #include <_PDCLIB_test.h>
+#include <string.h>
 
 int main( void )
 {
-    TESTCASE( NO_TESTDRIVER );
+    FILE * fh;
+    char buffer[10];
+    char const * fgets_test = "foo\nbar\0baz\nweenie";
+    TESTCASE( ( fh = fopen( testfile, "wb+" ) ) != NULL );
+    TESTCASE( fwrite( fgets_test, 1, 18, fh ) == 18 );
+    rewind( fh );
+    TESTCASE( fgets( buffer, 10, fh ) == buffer );
+    TESTCASE( strcmp( buffer, "foo\n" ) == 0 );
+    TESTCASE( fgets( buffer, 10, fh ) == buffer );
+    TESTCASE( memcmp( buffer, "bar\0baz\n", 8 ) == 0 );
+    TESTCASE( fgets( buffer, 10, fh ) == buffer );
+    TESTCASE( strcmp( buffer, "weenie" ) == 0 );
+    TESTCASE( feof( fh ) );
+    TESTCASE( fseek( fh, -1, SEEK_END ) == 0 );
+    TESTCASE( fgets( buffer, 1, fh ) == buffer );
+    TESTCASE( strcmp( buffer, "" ) == 0 );
+    TESTCASE( fgets( buffer, 0, fh ) == NULL );
+    TESTCASE( ! feof( fh ) );
+    TESTCASE( fgets( buffer, 1, fh ) == buffer );
+    TESTCASE( strcmp( buffer, "" ) == 0 );
+    TESTCASE( ! feof( fh ) );
+    TESTCASE( fgets( buffer, 2, fh ) == buffer );
+    TESTCASE( strcmp( buffer, "e" ) == 0 );
+    TESTCASE( fseek( fh, 0, SEEK_END ) == 0 );
+    TESTCASE( fgets( buffer, 2, fh ) == NULL );
+    TESTCASE( feof( fh ) );
+    TESTCASE( fclose( fh ) == 0 );
+    remove( testfile );
     return TEST_RESULTS;
 }
 
 #endif
+