first commit

2022-10-20 20:29:11 +08:00
commit 4d531f8044
3238 changed files with 1387862 additions and 0 deletions
@@ -0,0 +1,116 @@
+// do some non-destructive read tests relating text files
+
+#include <stdio.h>
+#include <string.h>
+
+static void readchars( FILE *fd ) {
+    int c;
+    while ( (c = fgetc(fd)) != EOF ) {
+	printf("c = %d", c);
+	if ( c == 10 ) {
+	    printf(" LF \\n");
+	}
+	if ( c == 13 ) {
+	    printf(" CR \\r");
+	}
+	printf("\n");
+    }
+}
+
+
+static void readlines( FILE *fd ) {
+    char line[256];
+    while ( fgets(line, 255, fd) != NULL ) {
+	int len = strlen(line);
+	printf("line = %s", line);
+	if ( len >= 2 ) {
+	    printf("  char[n - 1] = %d  char[n] = %d\n",
+		   line[len-2], line[len-1]);
+	} else if ( len >= 1 ) {
+	    printf("  char[n] = %d\n",line[len-1]);
+	} else {
+	    printf("empty string\n");
+	}
+    }
+}
+
+
+int main( int argc, char **argv ) {
+    // check usage
+    if ( argc != 2 ) {
+	printf("usage: %s file\n", argv[0]);
+	return -1;
+    }
+
+    char file[256];
+    strcpy( file, argv[1] );
+    FILE *fd;
+
+    // open a file in (default) text mode
+    printf("TEXT MODE (DEFAULT) by character\n\n");
+    fd = fopen( file, "r" );
+    if ( fd != NULL ) {
+	readchars( fd );
+	fclose(fd);
+    } else {
+	printf("Cannot open %s\n", file);
+    }
+    printf("\n");
+
+    // open a file in (explicit) text mode
+    printf("TEXT MODE (EXPLICIT) by character\n\n");
+    fd = fopen( file, "rt" );
+    if ( fd != NULL ) {
+	readchars( fd );
+	fclose(fd);
+    } else {
+	printf("Cannot open %s\n", file);
+    }
+    printf("\n");
+
+    // open a file in (explicit) binary mode
+    printf("BINARY MODE (EXPLICIT) by character\n\n");
+    fd = fopen( file, "rb" );
+    if ( fd != NULL ) {
+	readchars( fd );
+	fclose(fd);
+    } else {
+	printf("Cannot open %s\n", file);
+    }
+    printf("\n");
+
+    // open a file in (default) text mode
+    printf("TEXT MODE (DEFAULT) by line\n\n");
+    fd = fopen( file, "r" );
+    if ( fd != NULL ) {
+	readlines( fd );
+	fclose(fd);
+    } else {
+	printf("Cannot open %s\n", file);
+    }
+    printf("\n");
+
+    // open a file in (explicit) text mode
+    printf("TEXT MODE (EXPLICIT) by line\n\n");
+    fd = fopen( file, "rt" );
+    if ( fd != NULL ) {
+	readlines( fd );
+	fclose(fd);
+    } else {
+	printf("Cannot open %s\n", file);
+    }
+    printf("\n");
+
+    // open a file in (explicit) binary mode
+    printf("BINARY MODE (EXPLICIT) by line\n\n");
+    fd = fopen( file, "rb" );
+    if ( fd != NULL ) {
+	readlines( fd );
+	fclose(fd);
+    } else {
+	printf("Cannot open %s\n", file);
+    }
+    printf("\n");
+
+    return 0;
+}