sync

Makefile

@@ -11,12 +11,20 @@ PATCH = 1
 INCFLAGS  = $(shell echo $(SOURCE) | xargs printf -- '-I%s ')
 
 CCFLAGS  = -std=c89 -Wall -Wextra -pedantic -O2 
-CCFLAGS += -D_DEFAULT_SOURCE -DMAJOR=$(MAJOR) -DMINOR=$(MINOR) -DPATCH=$(PATCH) -DCHECK_LINK
+CCFLAGS += -DMAJOR=$(MAJOR) -DMINOR=$(MINOR) -DPATCH=$(PATCH) -DCHECK_LINK
 CCFLAGS += $(INCFLAGS)
 
 LDFLAGS = -s
 LDFLAGS += $(INCFLAGS)
 
+UNAME := $(shell uname)
+
+ifeq ($(UNAME), Linux)
+CCFLAGS += -D_GNU_SOURCE
+else 
+CCFLAGS += -D_DEFAULT_SOURCE
+endif
+
 BIN = bin
 APP = $(BIN)/app
 SRC = $(shell find $(SOURCE) -name "*.c")

command/sync.c

@@ -0,0 +1,85 @@
+#include "args.h"
+#include "command.h"
+#include "lslib.h"
+
+#define _X_OPEN_SOURCE 500
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+
+static struct {
+    bool sync_fs;
+    bool sync_data;
+} flags;
+
+static void help (void) {
+    printf("Usage: sync [-df] [FILE]...\n\n");
+    printf("Write all buffered blocks (in FILEs) to disk\n\n");
+	printf("\t-d\tAvoid syncing metadata\n");
+#ifdef _GNU_SOURCE
+	printf("\t-f\tSync filesystems underlying FILEs\n");
+#endif
+}
+
+static int short_arg (char c, char* next) {
+    UNUSED(next);
+    switch (c) {
+        case 'd':
+            flags.sync_data = true;
+            break;
+#ifdef _GNU_SOURCE
+        case 'f':
+            flags.sync_fs = true;
+            break;
+#endif
+        default:
+            return ARG_INVALID;
+    }
+    return ARG_UNUSED;
+}
+
+static bool sync_file(char* path) {
+    int fd;
+    int ret;
+
+    fd = open(path, O_NOCTTY | O_RDONLY | O_NONBLOCK);
+    if (fd < 0) {
+        return false;
+    }
+
+    if (flags.sync_fs) {
+#ifdef _GNU_SOURCE
+        ret = syncfs(fd) >= 0;
+#else 
+        ret = 0;
+#endif
+    } else {
+        ret = flags.sync_data ? fdatasync(fd) : fsync(fd);
+        if (ret < 0) {
+            error_s("failed to sync '%s': %s", path, strerror(errno));
+        }
+    }
+
+    close(fd);
+    return ret;
+}
+
+COMMAND(sync_cmd) {
+
+    int start, i, ret = EXIT_SUCCESS;
+    
+    start = parse_args(argc, argv, help, short_arg, NULL);
+
+    if (argc - start < 1) {
+        sync();
+        return EXIT_SUCCESS;
+    }
+
+    for (i = start; i < argc; i++) {
+        if (!sync_file(argv[i])) ret = EXIT_FAILURE;
+    }
+
+    return ret;
+}

command/tee.c

@@ -12,8 +12,8 @@ static struct {
 static void help(void) {
     printf("Usage: tee [-ai] [FILE]...\n\n");
     printf("Copy stdin to each FILE, and also to stdout\n\n");
-	printf("\t-a	Append to the given FILEs, don't overwrite\n");
-	printf("\t-i	Ignore interrupt signals (SIGINT)\n");
+	printf("\t-a\tAppend to the given FILEs, don't overwrite\n");
+	printf("\t-i\tIgnore interrupt signals (SIGINT)\n");
     exit(EXIT_SUCCESS);
 }
 
@@ -52,7 +52,7 @@ static int short_arg(char c, char* next) {
     return ARG_UNUSED;
 }
 
-COMMAND(tee) {
+COMMAND(tee_cmd) {
 
     int start, i;
     FILE** files;

readme.md

@@ -4,7 +4,8 @@
 A terrible busybox/gnu coreutils clone.
 
 Currently the only supported commands are: 
-`dd`, `cat`, `yes`, `echo`, `printf`, `id`, `groups`, `ls`, `tail`, `head`, `ed`, `tee`, `true`, `false`, `tee`, `whoami`, `wc`, `xargs`, `tac`, `rm`, `cp`, `mkdir`, `mv`, `grep`, `chown`, `chmod`
+`dd`, `cat`, `yes`, `echo`, `printf`, `id`, `groups`, `ls`, `tail`, `head`, `ed`, `tee`, `true`, `false`, `tee`, `whoami`, 
+`wc`, `xargs`, `tac`, `rm`, `cp`, `mkdir`, `mv`, `grep`, `chown`, `chmod`, `sync`
  
 ## How to
 

src/command.h

@@ -16,7 +16,7 @@ COMMAND(ls);
 COMMAND(tail);
 COMMAND(head);
 COMMAND(ed);
-COMMAND(tee);
+COMMAND(tee_cmd);
 COMMAND(whoami);
 COMMAND(wc);
 COMMAND(xargs);
@@ -28,5 +28,6 @@ COMMAND(mv);
 COMMAND(grep);
 COMMAND(chown_cmd);
 COMMAND(chmod_cmd);
+COMMAND(sync_cmd);
 
 #endif

src/main.c

@@ -23,7 +23,7 @@ int main (ARGUMENTS) {
         if (argc < 2) {
             printf("usage: lazysphere [function [arguments]...]\n\n");
             printf("currently defined functions:\n");
-            printf("\tdd, cat, yes, echo, printf, id, groups, ls, tail, head, ed, tee, true, false, tee, whoami, wc, xargs, tac, rm, cp, mkdir, mv, grep, chown, chmod\n");
+            printf("\tdd, cat, yes, echo, printf, id, groups, ls, tail, head, ed, tee, true, false, tee, whoami, wc, xargs, tac, rm, cp, mkdir, mv, grep, chown, chmod, sync\n");
             return EXIT_SUCCESS;
         }
         argc--;
@@ -62,7 +62,7 @@ int main (ARGUMENTS) {
     } else if (streql(cmd, "ed")) {
         return ed(NEXT_ARGS);
     } else if (streql(cmd, "tee")) {
-        return tee(NEXT_ARGS);
+        return tee_cmd(NEXT_ARGS);
     } else if (streql(cmd, "true")) {
         return EXIT_SUCCESS;
     } else if (streql(cmd, "false")) {
@@ -89,6 +89,8 @@ int main (ARGUMENTS) {
         return chown_cmd(NEXT_ARGS);
     } else if (streql(cmd, "chmod")) {
         return chmod_cmd(NEXT_ARGS);
+    } else if (streql(cmd, "sync")) {
+        return sync_cmd(NEXT_ARGS);
     } else {
         fprintf(stderr, "lazysphere: invalid command %s\n", cmd);
         return EXIT_FAILURE;