parse: Keep track of what files are already open

Fixes #22

6 files changed, 185 insertions, 50 deletions

diff --git a/cmdline.h b/cmdline.h
index 9a46f7f..7c1891c 100644
--- a/cmdline.h
+++ b/cmdline.h
@@ -50,6 +50,11 @@ struct root {
 };
 
 /**
+ * An open file for the command line.
+ */
+struct open_file;
+
+/**
  * The parsed command line.
  */
 struct cmdline {
@@ -89,7 +94,9 @@ struct cmdline {
 	/** The command line expression. */
 	struct expr *expr;
 
-	/** The number of open files used by the expression tree. */
+	/** All the open files owned by the command line. */
+	struct open_file *open_files;
+	/** The number of open files owned by the command line. */
 	int nopen_files;
 };
 
diff --git a/color.c b/color.c
index 1025c9e..8df6a1f 100644
--- a/color.c
+++ b/color.c
@@ -288,8 +288,6 @@ int cfclose(CFILE *cfile) {
 	if (cfile) {
 		if (cfile->close) {
 			ret = fclose(cfile->file);
-		} else if (cfile->file) {
-			ret = fflush(cfile->file);
 		}
 		free(cfile);
 	}
diff --git a/expr.h b/expr.h
index c0e2b92..0eba0da 100644
--- a/expr.h
+++ b/expr.h
@@ -219,9 +219,7 @@ void dump_expr(CFILE *cfile, const struct expr *expr, bool verbose);
 
 /**
  * Free an expression tree.
- *
- * @return 0 if successful, -1 on error.
  */
-int free_expr(struct expr *expr);
+void free_expr(struct expr *expr);
 
 #endif // EXPR_H
diff --git a/parse.c b/parse.c
index b4b7ddc..2708b9a 100644
--- a/parse.c
+++ b/parse.c
@@ -80,36 +80,23 @@ struct expr expr_false = {
 /**
  * Free an expression.
  */
-int free_expr(struct expr *expr) {
-	int ret = 0;
-
-	if (expr && expr != &expr_true && expr != &expr_false) {
-		if (expr->cfile && expr->cfile->close) {
-			if (cfclose(expr->cfile) != 0) {
-				perror("cfclose()");
-				ret = -1;
-			}
-		}
-
-		if (expr->regex) {
-			regfree(expr->regex);
-			free(expr->regex);
-		}
+void free_expr(struct expr *expr) {
+	if (!expr || expr == &expr_true || expr == &expr_false) {
+		return;
+	}
 
-		free_bfs_printf(expr->printf);
-		free_bfs_exec(expr->execbuf);
+	if (expr->regex) {
+		regfree(expr->regex);
+		free(expr->regex);
+	}
 
-		if (free_expr(expr->lhs) != 0) {
-			ret = -1;
-		}
-		if (free_expr(expr->rhs) != 0) {
-			ret = -1;
-		}
+	free_bfs_printf(expr->printf);
+	free_bfs_exec(expr->execbuf);
 
-		free(expr);
-	}
+	free_expr(expr->lhs);
+	free_expr(expr->rhs);
 
-	return ret;
+	free(expr);
 }
 
 struct expr *new_expr(eval_fn *eval, size_t argc, char **argv) {
@@ -232,27 +219,60 @@ void dump_expr(CFILE *cfile, const struct expr *expr, bool verbose) {
 }
 
 /**
+ * An open file for the command line.
+ */
+struct open_file {
+	/** The file itself. */
+	CFILE *cfile;
+	/** The path to the file (for diagnostics). */
+	const char *path;
+	/** Device number (for deduplication). */
+	dev_t dev;
+	/** Inode number (for deduplication). */
+	ino_t ino;
+	/** The next open file in the chain. */
+	struct open_file *next;
+};
+
+/**
  * Free the parsed command line.
  */
 int free_cmdline(struct cmdline *cmdline) {
 	int ret = 0;
 
 	if (cmdline) {
-		if (free_expr(cmdline->expr) != 0) {
-			ret = -1;
-		}
+		CFILE *cout = cmdline->cout;
+		CFILE *cerr = cmdline->cerr;
+
+		free_expr(cmdline->expr);
 
 		free_bfs_mtab(cmdline->mtab);
 
-		if (cfclose(cmdline->cerr) != 0) {
-			perror("cfclose()");
-			ret = -1;
+		struct open_file *ofile = cmdline->open_files;
+		while (ofile) {
+			struct open_file *next = ofile->next;
+
+			if (cfclose(ofile->cfile) != 0) {
+				if (cerr) {
+					cfprintf(cerr, "%{er}error: '%s': %s%{rs}\n", ofile->path, strerror(errno));
+				}
+				ret = -1;
+			}
+
+			free(ofile);
+			ofile = next;
 		}
-		if (cfclose(cmdline->cout) != 0) {
-			perror("cfclose()");
+
+		if (cout && fflush(cout->file) != 0) {
+			if (cerr) {
+				cfprintf(cerr, "%{er}error: standard output: %s%{rs}\n", strerror(errno));
+			}
 			ret = -1;
 		}
 
+		cfclose(cout);
+		cfclose(cerr);
+
 		free_colors(cmdline->colors);
 
 		struct root *root = cmdline->roots;
@@ -349,14 +369,52 @@ static void init_print_expr(struct parser_state *state, struct expr *expr) {
  * Open a file for an expression.
  */
 static int expr_open(struct parser_state *state, struct expr *expr, const char *path) {
-	expr->cfile = cfopen(path, state->use_color ? state->cmdline->colors : NULL);
-	if (!expr->cfile) {
-		cfprintf(state->cmdline->cerr, "%{er}error: '%s': %s%{rs}\n", path, strerror(errno));
-		return -1;
+	int ret = -1;
+
+	struct cmdline *cmdline = state->cmdline;
+
+	CFILE *cfile = cfopen(path, state->use_color ? cmdline->colors : NULL);
+	if (!cfile) {
+		cfprintf(cmdline->cerr, "%{er}error: '%s': %s%{rs}\n", path, strerror(errno));
+		goto out;
 	}
 
-	++state->cmdline->nopen_files;
-	return 0;
+	struct stat sb;
+	if (fstat(fileno(cfile->file), &sb) != 0) {
+		cfprintf(cmdline->cerr, "%{er}error: '%s': %s%{rs}\n", path, strerror(errno));
+		goto out_close;
+	}
+
+	for (struct open_file *ofile = cmdline->open_files; ofile; ofile = ofile->next) {
+		if (ofile->dev == sb.st_dev && ofile->ino == sb.st_ino) {
+			expr->cfile = ofile->cfile;
+			ret = 0;
+			goto out_close;
+		}
+	}
+
+	struct open_file *ofile = malloc(sizeof(*ofile));
+	if (!ofile) {
+		goto out_close;
+	}
+
+	ofile->cfile = cfile;
+	ofile->path = path;
+	ofile->dev = sb.st_dev;
+	ofile->ino = sb.st_ino;
+	ofile->next = cmdline->open_files;
+	cmdline->open_files = ofile;
+	++cmdline->nopen_files;
+
+	expr->cfile = cfile;
+
+	ret = 0;
+	goto out;
+
+out_close:
+	cfclose(cfile);
+out:
+	return ret;
 }
 
 /**
@@ -2932,6 +2990,7 @@ struct cmdline *parse_cmdline(int argc, char *argv[]) {
 	cmdline->xargs_safe = false;
 	cmdline->ignore_races = false;
 	cmdline->expr = &expr_true;
+	cmdline->open_files = NULL;
 	cmdline->nopen_files = 0;
 
 	cmdline->argv = malloc((argc + 1)*sizeof(*cmdline->argv));
diff --git a/tests.sh b/tests.sh
index 0f52581..9775292 100755
--- a/tests.sh
+++ b/tests.sh
@@ -330,6 +330,7 @@ gnu_tests=(
     test_flag_weird_names
     test_follow_comma
     test_fprint
+    test_fprint_duplicate
     test_double_dash
     test_flag_double_dash
     test_ignore_readdir_race
@@ -931,16 +932,31 @@ function test_follow_comma() {
 }
 
 function test_fprint() {
+    invoke_bfs basic -fprint scratch/test_fprint.out
+    sort -o scratch/test_fprint.out scratch/test_fprint.out
+
     if [ "$UPDATE" ]; then
-        invoke_bfs basic -fprint "$TESTS/test_fprint.out"
-        sort -o "$TESTS/test_fprint.out" "$TESTS/test_fprint.out"
+        cp scratch/test_fprint.out "$TESTS/test_fprint.out"
     else
-        invoke_bfs basic -fprint scratch/test_fprint.out
-        sort -o scratch/test_fprint.out scratch/test_fprint.out
         diff -u scratch/test_fprint.out "$TESTS/test_fprint.out"
     fi
 }
 
+function test_fprint_duplicate() {
+    touchp scratch/test_fprint_duplicate.out
+    ln scratch/test_fprint_duplicate.out scratch/test_fprint_duplicate.hard
+    ln -s test_fprint_duplicate.out scratch/test_fprint_duplicate.soft
+
+    invoke_bfs basic -fprint scratch/test_fprint_duplicate.out -fprint scratch/test_fprint_duplicate.hard -fprint scratch/test_fprint_duplicate.soft
+    sort -o scratch/test_fprint_duplicate.out scratch/test_fprint_duplicate.out
+
+    if [ "$UPDATE" ]; then
+        cp scratch/test_fprint_duplicate.out "$TESTS/test_fprint_duplicate.out"
+    else
+        diff -u scratch/test_fprint_duplicate.out "$TESTS/test_fprint_duplicate.out"
+    fi
+}
+
 function test_double_dash() {
     cd basic
     bfs_diff -- . -type f
diff --git a/tests/test_fprint_duplicate.out b/tests/test_fprint_duplicate.out
new file mode 100644
index 0000000..2575f35
--- /dev/null
+++ b/tests/test_fprint_duplicate.out
@@ -0,0 +1,57 @@
+basic
+basic
+basic
+basic/a
+basic/a
+basic/a
+basic/b
+basic/b
+basic/b
+basic/c
+basic/c
+basic/c
+basic/c/d
+basic/c/d
+basic/c/d
+basic/e
+basic/e
+basic/e
+basic/e/f
+basic/e/f
+basic/e/f
+basic/g
+basic/g
+basic/g
+basic/g/h
+basic/g/h
+basic/g/h
+basic/i
+basic/i
+basic/i
+basic/j
+basic/j
+basic/j
+basic/j/foo
+basic/j/foo
+basic/j/foo
+basic/k
+basic/k
+basic/k
+basic/k/foo
+basic/k/foo
+basic/k/foo
+basic/k/foo/bar
+basic/k/foo/bar
+basic/k/foo/bar
+basic/l
+basic/l
+basic/l
+basic/l/foo
+basic/l/foo
+basic/l/foo
+basic/l/foo/bar
+basic/l/foo/bar
+basic/l/foo/bar
+basic/l/foo/bar/baz
+basic/l/foo/bar/baz
+basic/l/foo/bar/baz