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elkscmd/file_utils/cp.c: add options -b, -n, -v, -u and updated usage

PATCH In review Nils Stec 2 participants 4 messages Apr 1, 2015

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Nils Stec

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#0 lore raw

PATCH 1/1 elkscmd/file_utils/cp.c: add options -b, -n, -v, -u and updated usage

Here's my updated patch. I think this attempt is better than the first, if you still find something annoying i will fix/change it.

This patch add some command line options to cp:

-b    make backup if file exists
-n    no clobber
-v    be verbose
-u    overwrite if source is newer than destintation file

I also tried to add "-i" (interactive), but i still need to figure out how to ask for just one keypress (y/n) without pressing return... Everything for that is prepared, in usage-text -i is commented out.

Hope you like this,
Nils

elkscmd/file_utils/cp.c +92 -8
index 6e23864..b881af0 100644
@@ -20,11 +20,25 @@
 #include <grp.h>
 #include <utime.h>
 #include <errno.h>
+#include <stdint.h>
 
 #define BUF_SIZE 4096
 
 static char *buf;
 
+/* macros for flag setting/clearing/testing */
+#define ISFLAG(a) 		((flags & a) == a)
+#define SETFLAG(a) 		(flags |= a)
+#define CLRFLAG(a)		(flags &= ~(a))
+
+/* some flags for command-line-options */
+static uint16_t flags;
+#define OPT_NOCLOBBER		0x0001
+#define OPT_VERBOSE		0x0002
+#define OPT_INTERACTIVE		0x0004
+#define OPT_BACKUP		0x0008
+#define OPT_BACKUPMADE		0x0010
+#define OPT_UPDATE		0x0020
 
 /*
  * Build a path name from the specified directory name and file name.

@@ -67,6 +81,9 @@ int isadir(char *name)
  * and modes.  Returns 1 if successful, or 0 on a failure with an
  * error message output.  (Failure is not indicated if the attributes cannot
  * be set.)
+ *
+ * Returns -1 if OPT_NOCLOBBER is set and a file is skipped if existent.
+ * This "skipped-file-indicator" is not used atm.
  */
 int copyfile(char *srcname, char *destname, int setmodes)
 {

@@ -78,15 +95,38 @@ int copyfile(char *srcname, char *destname, int setmodes)
 	struct	stat	statbuf1;
 	struct	stat	statbuf2;
 	struct	utimbuf	times;
+	static  char    backupname[PATHLEN];
 
+	/* source nonexistent */
 	if (stat(srcname, &statbuf1) < 0) {
 		perror(srcname);
 		return 0;
 	}
 
+	/* destination nonexistent */
 	if (stat(destname, &statbuf2) < 0) {
 		statbuf2.st_ino = -1;
 		statbuf2.st_dev = -1;
+	} else {	/* destination existent */
+		if (ISFLAG(OPT_BACKUP)) {
+			strcpy(backupname, destname);
+			strcat(backupname, "~");
+			rename(destname, backupname);
+			SETFLAG(OPT_BACKUPMADE);
+		} else if (ISFLAG(OPT_UPDATE)) {
+			/* if dest is newer than source, don't overwrite it */
+			if (statbuf1.st_mtime < statbuf2.st_mtime) return -1;
+		} else if (ISFLAG(OPT_NOCLOBBER)) {
+			return -1;
+		} else if (ISFLAG(OPT_INTERACTIVE)) {
+			/* TODO fix this, getchar wants return */
+			/*
+			 * fprintf(stderr, "really overwrite '%s'? (y/n) \n", destname);
+			if(getchar() != 'y') {
+				return -1;
+			}
+			*/
+		}
 	}
 
 	if ((statbuf1.st_dev == statbuf2.st_dev) &&

@@ -143,9 +183,14 @@ int copyfile(char *srcname, char *destname, int setmodes)
 		(void) utime(destname, &times);
 	}
 
+	if (ISFLAG(OPT_BACKUPMADE) && ISFLAG(OPT_VERBOSE)) {
+		fprintf(stderr, "`%s' -> `%s' (backup: `%s')\n", srcname, destname, backupname);
+		CLRFLAG(OPT_BACKUPMADE);
+	}
+	else if (ISFLAG(OPT_VERBOSE))
+		fprintf(stderr, "`%s' -> `%s'\n", srcname, destname);
 	return 1;
 
-
 error_exit:
 	close(rfd);
 	close(wfd);

@@ -157,37 +202,76 @@ error_exit:
 int main(int argc, char **argv)
 {
 	int	dirflag;
+	int     arg_cnt;
+	int	opt_cnt;
+	int	retval;
+	unsigned int file_count;
 	char	*srcname;
 	char	*destname;
 	char	*lastarg;
 
 	if (argc < 3) goto usage;
 
+	/* lastarg is copy destination */
 	lastarg = argv[argc - 1];
 
 	dirflag = isadir(lastarg);
 
-	if ((argc > 3) && !dirflag) {
-		fprintf(stderr, "%s: not a directory\n", lastarg);
+	flags = 0;
+	opt_cnt = 0;
+
+	arg_cnt = 1;	/* start at argv[1] */
+	while(arg_cnt < argc) {
+		if (!strcmp(argv[arg_cnt], "-n")) {
+			SETFLAG(OPT_NOCLOBBER);
+		} else if (!strcmp(argv[arg_cnt], "-v")) {
+			SETFLAG(OPT_VERBOSE);
+		} else if (!strcmp(argv[arg_cnt], "-i")) {
+			SETFLAG(OPT_INTERACTIVE);
+		} else if (!strcmp(argv[arg_cnt], "-u")) {
+			SETFLAG(OPT_UPDATE);
+		} else if (!strcmp(argv[arg_cnt], "-b")) {
+			SETFLAG(OPT_BACKUP);
+		} else if (!strcmp(argv[arg_cnt], "-h")) goto usage;
+		else break;
+		opt_cnt++;
+		arg_cnt++;
+	}
+	opt_cnt++;
+
+	/* if multiple files are specified, last one must be a directory */
+	if ((argc > (opt_cnt + 2)) && !dirflag) {
+		fprintf(stderr, "%s is not a directory\n", lastarg);
 		exit(1);
 	}
 
 	buf = malloc(BUF_SIZE);
-	while (argc-- > 2) {
-		srcname = argv[1];
+	file_count = 0;
+	while (argc-- > (opt_cnt + 1)) {
+		srcname = argv[opt_cnt+file_count];
 		destname = lastarg;
 		if (dirflag) destname = buildname(destname, srcname);
 
-		if (!copyfile(*++argv, destname, 0)) goto error_copy;
+		retval = copyfile(srcname, destname, 0);
+		if (!retval) goto error_copy;
+		file_count++;
 	}
 	free(buf);
+
 	exit(0);
 
 error_copy:
 	fprintf(stderr, "Failed to copy %s -> %s\n", srcname, destname);
 	exit(1);
 usage:
-	fprintf(stderr, "usage: %s source_file dest_file\n", argv[0]);
-	fprintf(stderr, "       %s file1 file2 ... dest_directory\n", argv[0]);
+	fprintf(stderr, "usage: %s [options] source_file dest_file\n", argv[0]);
+	fprintf(stderr, "       %s [options] file1 file2 ... dest_directory\n", argv[0]);
+	fprintf(stderr, "options:  -b   make a backup of each exisiting destination file\n");
+	fprintf(stderr, "               -b overrides -u (update)\n");
+	fprintf(stderr, "          -n   no overwriting, no clobber\n");
+	fprintf(stderr, "          -v   be verbose\n");
+/*	fprintf(stderr, "          -i   interactive, prompt before overwrite\n");
+	fprintf(stderr, "               -b, -u and -n override interactive mode\n");*/
+	fprintf(stderr, "          -u   copy only if source file is newer than destination file\n");
 	exit(1);
 }
#1 lore raw

On 4/1/2015 7:22 AM, Nils Stec wrote:
+ * Returns -1 if OPT_NOCLOBBER is set and a file is skipped if existent.
...
+ } else if (ISFLAG(OPT_NOCLOBBER)) {
+ return -1;
...
+ retval = copyfile(srcname, destname, 0);
+ if (!retval) goto error_copy;

This causes an error to be returned if someone asks for no clobbering.
Doing what is asked for by the user should never be an error condition
and should return success unless a true error occurred (i.e. write
errors). Here's example output when using the -n switch with GNU coreutils 'cp' and testing for any error conditions:

$ ls -l foo bar
bar:
total 0
-rw-r--r-- 1 user user 0 Apr  1 07:31 1
-rw-r--r-- 1 user user 0 Apr  1 07:31 2

foo:
total 12

-rw-r--r-- 1 user user 4 Apr  1 07:31 1
-rw-r--r-- 1 user user 4 Apr  1 07:31 2
-rw-r--r-- 1 user user 4 Apr  1 07:31 3
$ cp -n foo/* bar/ || echo error
$ cp -n foo/* bar/ && echo success
success
$ ls -l foo bar
bar:
total 4
-rw-r--r-- 1 user user 0 Apr  1 07:31 1
-rw-r--r-- 1 user user 0 Apr  1 07:31 2
-rw-r--r-- 1 user user 4 Apr  1 07:32 3

foo:
total 12

-rw-r--r-- 1 user user 4 Apr  1 07:31 1
-rw-r--r-- 1 user user 4 Apr  1 07:31 2
-rw-r--r-- 1 user user 4 Apr  1 07:31 3

$

author
#2 lore raw
Quoted 40 lines · Jody Bruchon

On 4/1/2015 7:22 AM, Nils Stec wrote:
+ * Returns -1 if OPT_NOCLOBBER is set and a file is skipped if existent.
...

(quoted diff) +4 -0
+        } else if (ISFLAG(OPT_NOCLOBBER)) {
+            return -1;
...
+        retval = copyfile(srcname, destname, 0);
+        if (!retval) goto error_copy;

This causes an error to be returned if someone asks for no clobbering.
Doing what is asked for by the user should never be an error condition
and should return success unless a true error occurred (i.e. write
errors). Here's example output when using the -n switch with GNU coreutils 'cp' and testing for any error conditions:

$ ls -l foo bar
bar:
total 0
(quoted diff) +0 -2
-rw-r--r-- 1 user user 0 Apr  1 07:31 1
-rw-r--r-- 1 user user 0 Apr  1 07:31 2

foo:
total 12

(quoted diff) +0 -3
-rw-r--r-- 1 user user 4 Apr  1 07:31 1
-rw-r--r-- 1 user user 4 Apr  1 07:31 2
-rw-r--r-- 1 user user 4 Apr  1 07:31 3

$ cp -n foo/* bar/ || echo error
$ cp -n foo/* bar/ && echo success
success
$ ls -l foo bar
bar:
total 4
(quoted diff) +0 -3
-rw-r--r-- 1 user user 0 Apr  1 07:31 1
-rw-r--r-- 1 user user 0 Apr  1 07:31 2
-rw-r--r-- 1 user user 4 Apr  1 07:32 3

foo:
total 12

(quoted diff) +0 -3
-rw-r--r-- 1 user user 4 Apr  1 07:31 1
-rw-r--r-- 1 user user 4 Apr  1 07:31 2
-rw-r--r-- 1 user user 4 Apr  1 07:31 3
Quoted 6 lines

$

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elkscmd/file_utils/cp.c +89 -8
index 6e23864..2e413e9 100644
@@ -20,11 +20,25 @@
 #include <grp.h>
 #include <utime.h>
 #include <errno.h>
+#include <stdint.h>
 
 #define BUF_SIZE 4096
 
 static char *buf;
 
+/* macros for flag setting/clearing/testing */
+#define ISFLAG(a) 		((flags & a) == a)
+#define SETFLAG(a) 		(flags |= a)
+#define CLRFLAG(a)		(flags &= ~(a))
+
+/* some flags for command-line-options */
+static uint16_t flags;
+#define OPT_NOCLOBBER		0x0001
+#define OPT_VERBOSE		0x0002
+#define OPT_INTERACTIVE		0x0004
+#define OPT_BACKUP		0x0008
+#define OPT_BACKUPMADE		0x0010
+#define OPT_UPDATE		0x0020
 
 /*
  * Build a path name from the specified directory name and file name.

@@ -78,15 +92,38 @@ int copyfile(char *srcname, char *destname, int setmodes)
 	struct	stat	statbuf1;
 	struct	stat	statbuf2;
 	struct	utimbuf	times;
+	static  char    backupname[PATHLEN];
 
+	/* source nonexistent */
 	if (stat(srcname, &statbuf1) < 0) {
 		perror(srcname);
 		return 0;
 	}
 
+	/* destination nonexistent */
 	if (stat(destname, &statbuf2) < 0) {
 		statbuf2.st_ino = -1;
 		statbuf2.st_dev = -1;
+	} else {	/* destination existent */
+		if (ISFLAG(OPT_BACKUP)) {
+			strcpy(backupname, destname);
+			strcat(backupname, "~");
+			rename(destname, backupname);
+			SETFLAG(OPT_BACKUPMADE);
+		} else if (ISFLAG(OPT_UPDATE)) {
+			/* if dest is newer than source, don't overwrite it */
+			if (statbuf1.st_mtime < statbuf2.st_mtime) return 1;
+		} else if (ISFLAG(OPT_NOCLOBBER)) {
+			return 1;
+		} else if (ISFLAG(OPT_INTERACTIVE)) {
+			/* TODO fix this, getchar wants return */
+			/*
+			 * fprintf(stderr, "really overwrite '%s'? (y/n) \n", destname);
+			if(getchar() != 'y') {
+				return -1;
+			}
+			*/
+		}
 	}
 
 	if ((statbuf1.st_dev == statbuf2.st_dev) &&

@@ -143,9 +180,14 @@ int copyfile(char *srcname, char *destname, int setmodes)
 		(void) utime(destname, &times);
 	}
 
+	if (ISFLAG(OPT_BACKUPMADE) && ISFLAG(OPT_VERBOSE)) {
+		fprintf(stderr, "`%s' -> `%s' (backup: `%s')\n", srcname, destname, backupname);
+		CLRFLAG(OPT_BACKUPMADE);
+	}
+	else if (ISFLAG(OPT_VERBOSE))
+		fprintf(stderr, "`%s' -> `%s'\n", srcname, destname);
 	return 1;
 
-
 error_exit:
 	close(rfd);
 	close(wfd);

@@ -157,37 +199,76 @@ error_exit:
 int main(int argc, char **argv)
 {
 	int	dirflag;
+	int     arg_cnt;
+	int	opt_cnt;
+	int	retval;
+	unsigned int file_count;
 	char	*srcname;
 	char	*destname;
 	char	*lastarg;
 
 	if (argc < 3) goto usage;
 
+	/* lastarg is copy destination */
 	lastarg = argv[argc - 1];
 
 	dirflag = isadir(lastarg);
 
-	if ((argc > 3) && !dirflag) {
-		fprintf(stderr, "%s: not a directory\n", lastarg);
+	flags = 0;
+	opt_cnt = 0;
+
+	arg_cnt = 1;	/* start at argv[1] */
+	while(arg_cnt < argc) {
+		if (!strcmp(argv[arg_cnt], "-n")) {
+			SETFLAG(OPT_NOCLOBBER);
+		} else if (!strcmp(argv[arg_cnt], "-v")) {
+			SETFLAG(OPT_VERBOSE);
+		} else if (!strcmp(argv[arg_cnt], "-i")) {
+			SETFLAG(OPT_INTERACTIVE);
+		} else if (!strcmp(argv[arg_cnt], "-u")) {
+			SETFLAG(OPT_UPDATE);
+		} else if (!strcmp(argv[arg_cnt], "-b")) {
+			SETFLAG(OPT_BACKUP);
+		} else if (!strcmp(argv[arg_cnt], "-h")) goto usage;
+		else break;
+		opt_cnt++;
+		arg_cnt++;
+	}
+	opt_cnt++;
+
+	/* if multiple files are specified, last one must be a directory */
+	if ((argc > (opt_cnt + 2)) && !dirflag) {
+		fprintf(stderr, "%s is not a directory\n", lastarg);
 		exit(1);
 	}
 
 	buf = malloc(BUF_SIZE);
-	while (argc-- > 2) {
-		srcname = argv[1];
+	file_count = 0;
+	while (argc-- > (opt_cnt + 1)) {
+		srcname = argv[opt_cnt+file_count];
 		destname = lastarg;
 		if (dirflag) destname = buildname(destname, srcname);
 
-		if (!copyfile(*++argv, destname, 0)) goto error_copy;
+		retval = copyfile(srcname, destname, 0);
+		if (!retval) goto error_copy;
+		file_count++;
 	}
 	free(buf);
+
 	exit(0);
 
 error_copy:
 	fprintf(stderr, "Failed to copy %s -> %s\n", srcname, destname);
 	exit(1);
 usage:
-	fprintf(stderr, "usage: %s source_file dest_file\n", argv[0]);
-	fprintf(stderr, "       %s file1 file2 ... dest_directory\n", argv[0]);
+	fprintf(stderr, "usage: %s [options] source_file dest_file\n", argv[0]);
+	fprintf(stderr, "       %s [options] file1 file2 ... dest_directory\n", argv[0]);
+	fprintf(stderr, "options:  -b   make a backup of each exisiting destination file\n");
+	fprintf(stderr, "               -b overrides -u (update)\n");
+	fprintf(stderr, "          -n   no overwriting, no clobber\n");
+	fprintf(stderr, "          -v   be verbose\n");
+/*	fprintf(stderr, "          -i   interactive, prompt before overwrite\n");
+	fprintf(stderr, "               -b, -u and -n override interactive mode\n");*/
+	fprintf(stderr, "          -u   copy only if source file is newer than destination file\n");
 	exit(1);
 }
#3 lore raw
In reply to Jody Bruchon
Quoted 1 line · Jody Bruchon

This causes an error to be returned if someone asks for no clobbering.

I should drink more caffeine before reading code in the morning; it seems that this statement is not correct after all. I can't seem to apply the patch against master though.