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minix3/commands/backup/backup.c

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/* backup - backup a directory Author: Andy Tanenbaum */
/* This program recursively backs up a directory. It has two typical uses:
*
* 1. Backing up a directory to 1 or more diskettes
* 2. Backing up RAM disk to a shadow directory on hard disk
*
* The backup directory or medium may be empty, in which case, the entire
* source directory is copied, or it may contain an old backup, in which
* case only those files that are new or out of date are copied. In this
* respect, 'backup' resembles 'make', except that no 'makefile' is needed.
* The backed up copy may optionally be compressed to save space.
*
* The following flags exist:
*
* -d At the top level, only back up directories (not loose files)
* -j Don't copy junk: *.Z, *.bak, *.log, a.out, and core
* -m If ENOSPC encountered, ask for another diskette
* -n No directories, only loose files are backed up
* -o Don't copy *.o files
* -r Restore files (ie. uncompress if necessary)
* -s Don't copy *.s files
* -t Set creation date of target-file equal to cdate of source-file
* -v Verbose (announce what is being done)
* -z Compress on backup/uncompress on restore
*
* Patches:
* 30 Mar 91. Added restore option. cwr.
* 9 Sep 91. Changed user interface. cwr.
* 21 Jan 93. Revised error messages. cwr.
* 29 Mar 95. Added -o, NARROW define. cwr.
* 16 Nov 2013. Changed the functions to ANSI style.
* Author: Alexandre Beletti (rhiguita@gmail.com)
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/syslimits.h>
#include <errno.h>
#include <fcntl.h>
#include <utime.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/wait.h>
#include <stdio.h>
#include <dirent.h>
#define NAME_SIZE NAME_MAX
#undef NARROW /* Width of verbose output */
#define COPY_SIZE 4096
#define MAX_ENTRIES 512
#define MAX_PATH 256
#define NONFATAL 0
#define FATAL 1
#define NO_SAVINGS 512 /* compress can return code 2 */
#define OUT_OF_SPACE 2
struct dirent_full {
struct dirent de;
char d_name[MAXNAMLEN+1];
} dir_ent[MAX_ENTRIES];
int entries = 0;
struct sorted {
int mode; /* file mode */
char *namep; /* pointer to name in dir_buf */
long acctime; /* time of last access */
long modtime; /* time of last modification */
} sorted[MAX_ENTRIES];
char copybuf[COPY_SIZE];
char *pname;
int dflag, jflag, mflag, nflag, oflag, rflag, sflag, tflag, vflag, zflag;
extern int errno;
extern char **environ;
int main(int argc, char *argv[]);
void maketarget(char *dir2);
int make_dir(char *dir);
int stat_all(char *dir1, int n);
void sort_dir(int m);
void process(int m, char *dir1, char *dir2);
void swap(struct sorted *sp1, struct sorted *sp2);
int copy(char *dir1, struct sorted *sp, char *cbuf2);
int zcopy(char *src, char *targ);
void copydir(char *dir1, char *dir2, char *namep);
void newdisk(char *dir);
void usage(void);
void error(int type, char *s1, char *s2, char *s3);
int main(int argc, char *argv[])
{
int n, m;
char *dir1, *dir2, *cp, c;
struct stat s;
struct dirent *e;
DIR *DIR1;
(void) sync();
/* Get the flags */
if ((pname = strrchr(argv[0], '/')) == (char *)NULL)
pname = argv[0];
else
pname++;
if (argc < 3 || argc > 4) usage();
if (argc == 4) {
cp = argv[1];
if (*cp++ != '-') usage();
while ((c = *cp++) != '\0') {
switch (c) {
case 'd': dflag++; break;
case 'j': jflag++; break;
case 'm': mflag++; break;
case 'n': nflag++; break;
case 'o': oflag++; break;
case 's': sflag++; break;
case 'r': rflag++; break;
case 't': tflag++; break;
case 'v': vflag++; break;
case 'z': zflag++; break;
default: usage();
}
}
dir1 = argv[2];
dir2 = argv[3];
} else {
dir1 = argv[1];
dir2 = argv[2];
}
if (!strcmp(pname, "restore") && !rflag) rflag++;
/* Check for a valid source */
if (stat(dir1, &s) < 0) error(FATAL, "cannot stat ", dir1, "");
if ((s.st_mode & S_IFMT) != S_IFDIR) error(FATAL, "non-directory ", dir1, "");
/* Read in the source directory */
if(!(DIR1 = opendir(dir1))) {
perror(dir1);
return 1;
}
for(entries = 0; entries < MAX_ENTRIES && (e=readdir(DIR1)); entries++) {
memcpy(&dir_ent[entries].de, e, sizeof(*e));
snprintf(dir_ent[entries].d_name, MAXNAMLEN, "%s", e->d_name);
}
closedir(DIR1);
if (entries == MAX_ENTRIES)
error(FATAL, "directory ", dir1, " is too large");
/* Create the target directory. */
maketarget(dir2);
/* Stat all the entries. */
n = entries;
m = stat_all(dir1, n);
/* Remove non-entries and sort what's left. */
sort_dir(m);
/* Process each of the m entries one at a time. */
process(m, dir1, dir2);
return(0);
}
void maketarget(char *dir2)
{
/* The target directory is created if it does not already exist. */
char *p, c, dbuf[MAX_PATH];
if (access(dir2, 6) == 0)
return; /* if target exists, we're done */
if (make_dir(dir2) == 0) return; /* we just made it */
/* We have to try creating all the higher level directories. */
strcpy(dbuf, dir2);
p = dbuf + 1;
while (1) {
while (*p != '/' && *p != '\0') p++;
c = *p; /* either / or \0 */
*p = 0;
make_dir(dbuf);
if (c == '\0') return;
*p = c;
p++;
}
}
int make_dir(char *dir)
{
/* Create a directory. */
int pid, status;
if ((pid = fork()) < 0)
error(FATAL, "cannot fork off mkdir to create ", dir, "");
if (pid > 0) {
/* Parent process waits for child (mkdir). */
wait(&status);
return(status);
} else {
/* Child process executes mkdir */
close(2); /* don't want mkdir's error messages */
execle("/bin/mkdir", "mkdir", dir, (char *) 0, environ);
execle("/usr/bin/mkdir", "mkdir", dir, (char *) 0, environ);
error(FATAL, "cannot execute mkdir", "", "");
}
return(0);
}
int stat_all(char *dir1, int n)
{
/* Stat all the directory entries. By doing this all at once, the disk
* head can stay in the inode area.
*/
int i, j;
char cbuf[MAX_PATH];
struct stat s;
for (i = 0; i < n; i++) {
/* Mark "." and ".." as null entries, as well as unstatable ones. */
if (strcmp(dir_ent[i].d_name, ".") == 0) dir_ent[i].de.d_ino = 0;
if (strcmp(dir_ent[i].d_name, "..") == 0) dir_ent[i].de.d_ino = 0;
if (dir_ent[i].de.d_ino == 0) continue;
/* Stat the file. */
snprintf(cbuf, sizeof(cbuf), "%s/%s", dir1, dir_ent[i].d_name);
if (stat(cbuf, &s) < 0) {
error(NONFATAL, "cannot stat ", cbuf, "");
dir_ent[i].de.d_ino = 0; /* mark as unusable */
continue;
}
sorted[i].mode = s.st_mode;
sorted[i].acctime = s.st_atime;
sorted[i].modtime = s.st_mtime;
sorted[i].namep = dir_ent[i].d_name;
sorted[i].namep[NAME_SIZE-1] = '\0';
}
/* Squeeze out all the entries whose ino field is 0. */
j = 0;
for (i = 0; i < n; i++) {
if (dir_ent[i].de.d_ino != 0) {
sorted[j] = sorted[i];
j++;
}
}
return(j);
}
void sort_dir(int m)
{
/* Sort the directory using bubble sort. */
struct sorted *sp1, *sp2;
for (sp1 = &sorted[0]; sp1 < &sorted[m - 1]; sp1++) {
for (sp2 = sp1 + 1; sp2 < &sorted[m]; sp2++) {
if (strcmp(sp1->namep, sp2->namep) > 0)
swap(sp1, sp2);
}
}
}
void process(int m, char *dir1, char *dir2)
{
/* Process each entry in sorted[]. If it is a regular file, stat the target
* file. The the source is newer, copy it. If the entry is a directory,
* recursively call the entire program to process the directory.
*/
int er, fmode, res;
struct sorted *sp;
struct stat s;
char cbuf[MAX_PATH];
for (sp = &sorted[0]; sp < &sorted[m]; sp++) {
int namlen;
fmode = sp->mode & S_IFMT;
if (fmode == S_IFREG) {
/* Regular file. Construct target name and stat it. */
snprintf(cbuf, sizeof(cbuf), "%s/%s", dir2, sp->namep);
namlen = strlen(sp->namep);
/* Switch between compressed and uncompressed file names */
if (zflag && !rflag && strncmp((sp->namep + namlen - 2), ".Z", (size_t)2)
&& (namlen <= (NAME_SIZE - 2)))
strncat(cbuf, ".Z", (size_t)2);
if (zflag && rflag && !strncmp((sp->namep + namlen - 2), ".Z", (size_t)2))
cbuf[strlen(cbuf) - 2] = '\0';
er = stat(cbuf, &s);
if (er < 0 || sp->modtime > s.st_mtime) {
res = copy(dir1, sp, cbuf);
} else {
res = NONFATAL;
}
/* Check status of the copy. */
if (res == OUT_OF_SPACE) {
printf("Out of space while copying to %s\n", cbuf);
/* We ran out of space copying a regular file. */
if (mflag == 0)
error(FATAL, "Quitting, disk full", "", "");
/* If -m, ask for new diskette and continue. */
newdisk(dir2);
sp--;
continue;
}
} else if (fmode == S_IFDIR) {
/* Directory. Execute this program recursively. */
copydir(dir1, dir2, sp->namep);
} else if (fmode == S_IFBLK || fmode == S_IFCHR) {
/* Special file. */
strncpy(cbuf, sp->namep, sizeof(cbuf));
printf("%s is special file. Not backed up.\n", cbuf);
}
}
}
void swap(struct sorted *sp1, struct sorted *sp2)
{
/* Swap two directory entries. */
struct sorted d;
d = *sp1;
*sp1 = *sp2;
*sp2 = d;
}
int copy(char *dir1, struct sorted *sp, char *cbuf2)
{
/* Copy a regular file. */
int fd1, fd2, nr, nw, res, n;
char cbuf1[MAX_PATH], *p;
#ifdef NARROW
char *msg = (rflag || strcmp(pname, "backup")) ? "Restored" : "Backing up";
#endif
/* If the -j or -o or -s flags were given, suppress certain files. */
p = sp->namep;
n = strlen(p);
if (n > NAME_SIZE) n = NAME_SIZE;
if (jflag) {
if (strcmp(p, "a.out") == 0) return(0);
if (strcmp(p, "core") == 0) return (0);
if (strcmp(p + n - 2, ".Z") == 0) return (0);
if (strcmp(p + n - 4, ".bak") == 0) return (0);
if (strcmp(p + n - 4, ".log") == 0) return (0);
}
if (oflag) {
if (strcmp(p + n - 2, ".o") == 0) return(0);
}
if (sflag) {
if (strcmp(p + n - 2, ".s") == 0) return(0);
}
res = 0;
if (dflag) return(0); /* backup -d means only directories */
strcpy(cbuf1, dir1);
strncat(cbuf1, "/", (size_t)1);
strncat(cbuf1, sp->namep, (size_t)NAME_SIZE); /* cbuf1 = source file name */
/* At this point, cbuf1 contains the source file name, cbuf2 the target. */
fd1 = open(cbuf1, O_RDONLY);
if (fd1 < 0) {
error(NONFATAL, "cannot open ", cbuf1, "");
return(res);
}
fd2 = creat(cbuf2, (sp->mode | S_IWUSR) & 07777);
if (fd2 < 0) {
if (errno == ENFILE) {
close(fd1);
return(OUT_OF_SPACE);
}
error(NONFATAL, "cannot create ", cbuf2, "");
close(fd1);
return(res);
}
/* Both files are now open. Do the copying. */
if ((!rflag && strncmp((sp->namep + n - 2), ".Z", (size_t)2)) ||
(rflag && !strncmp((sp->namep + n - 2), ".Z", (size_t)2))) {
if (zflag && (rflag || (n <= (NAME_SIZE - 2)))) {
close(fd1);
close(fd2);
res = zcopy(cbuf1, cbuf2);
if (tflag) utime(cbuf2, (struct utimbuf *) & (sp->acctime));
if (res != 0) unlink(cbuf2); /* if error, get rid of the corpse */
#ifdef NARROW
if (vflag && res == 0) printf("%s %s\n", msg, cbuf1);
#else
if (vflag && res == 0) {
printf("%-37.37s -> %-37.37s\n", cbuf1, cbuf2);
if (strlen(cbuf1) > 37 || strlen(cbuf2) > 37)
printf("%37.37s %37.37s\n",
(strlen(cbuf1) > 37) ? (cbuf1 + 37) : "",
(strlen(cbuf2) > 37) ? (cbuf2 + 37) : "");
}
#endif
return(res);
}
}
while (1) {
nr = read(fd1, copybuf, COPY_SIZE);
if (nr == 0) break;
if (nr < 0) {
error(NONFATAL, "read error on ", cbuf1, "");
res = EIO;
break;
}
nw = write(fd2, copybuf, nr);
if (nw < 0) {
if (errno == ENOSPC) {
/* Device is full. */
res = OUT_OF_SPACE;
break;
}
/* True write error. */
error(NONFATAL, "write error on ", cbuf2, "");
res = EIO;
break;
}
}
if (res == 0) {
#ifdef NARROW
if (vflag) printf("%s %s\n", msg, cbuf1);
#else
if (vflag) {
printf("%-37.37s -> %-37.37s\n", cbuf1, cbuf2);
if (strlen(cbuf1) > 37 || strlen(cbuf2) > 37)
printf("%37.37s %37.37s\n",
(strlen(cbuf1) > 37) ? (cbuf1 + 37) : "",
(strlen(cbuf2) > 37) ? (cbuf2 + 37) : "");
}
#endif
} else {
unlink(cbuf2);
}
close(fd1);
close(fd2);
if (tflag) utime(cbuf2, (struct utimbuf *) & (sp->acctime));
return(res);
}
int zcopy(char *src, char *targ)
{
int pid, status, res, s;
char fbuf[20];
/* These flags go for compress and gzip. */
strcpy(fbuf, "-c");
if (rflag)
strcat(fbuf, "d");
else
strcat(fbuf, "f");
if ((pid = fork()) < 0) error(FATAL, "cannot fork", "", "");
if (pid > 0) {
wait(&status);
/* Error codes 0 and 2 are ok, assume others mean disk is full. */
res = (status == 0 || status == NO_SAVINGS ? 0 : OUT_OF_SPACE);
return(res);
} else {
/* Child must execute compress. */
close(1);
s = open(targ, O_RDWR);
if (s < 0) error(FATAL, "cannot write on ", "targ", "");
execle("/usr/bin/gzip", "gzip", fbuf, src, (char *)0, environ);
execle("/usr/local/bin/gzip", "gzip", fbuf, src, (char *)0, environ);
execle("/bin/compress", "compress", fbuf, src, (char *)0, environ);
execle("/usr/bin/compress", "compress", fbuf, src, (char *)0, environ);
error(FATAL, "cannot exec gzip or compress", "", "");
}
return(0);
}
void copydir(char *dir1, char *dir2, char *namep)
{
/* Copy a directory. */
int pid, status;
char fbuf[20], d1buf[MAX_PATH], d2buf[MAX_PATH];
if (nflag) return; /* backup -n means no directories */
fbuf[0] = '\0';
/* Handle directory copy by forking off 'backup' ! */
if (jflag || mflag || oflag || rflag || sflag || tflag || vflag || zflag)
strcpy(fbuf, "-");
if (jflag) strcat(fbuf, "j");
if (mflag) strcat(fbuf, "m");
if (oflag) strcat(fbuf, "o");
if (rflag) strcat(fbuf, "r");
if (sflag) strcat(fbuf, "s");
if (tflag) strcat(fbuf, "t");
if (vflag) strcat(fbuf, "v");
if (zflag) strcat(fbuf, "z");
snprintf(d1buf, sizeof(d1buf), "%s/%s", dir1, namep);
snprintf(d2buf, sizeof(d2buf), "%s/%s", dir2, namep);
if ((pid = fork()) < 0) error(FATAL, "cannot fork", "", "");
if (pid > 0) {
/* Parent waits for child, then returns. */
wait(&status);
return;
}
if (fbuf[0] == '-') {
execle(pname, pname, fbuf, d1buf, d2buf, (char *) 0, environ);
execle("/bin/backup", "backup", fbuf, d1buf, d2buf, (char *)0,environ);
execle("/usr/bin/backup","backup",fbuf,d1buf,d2buf,(char *)0,environ);
error(FATAL, "cannot recursively exec backup", "", "");
} else {
execle(pname, pname, d1buf, d2buf, (char *) 0, environ);
execle("/bin/backup", "backup", d1buf, d2buf, (char *)0,environ);
execle("/usr/bin/backup","backup", d1buf, d2buf, (char *)0,environ);
error(FATAL, "cannot recursively exec backup", "", "");
}
}
void newdisk(char *dir)
{
/* Ask for a new diskette. A big problem is that this program does not
* know which device is being used and where it is mounted on. As an
* emergency solution, fork off a shell and ask the user to do the work.
*/
int pid, status;
printf("\nDiskette full. Please do the following:\n");
printf(" 1. Unmount the diskette using /etc/umount\n");
printf(" 2. Physically replace the diskette by the next one.\n");
printf(" 3. Mount the new diskette using /etc/mount\n");
printf(" 4. Type CTRL-D to return to the backup/restore program\n");
if ((pid = fork()) < 0) error(FATAL, "cannot fork", "", "");
if (pid > 0) {
wait(&status);
maketarget(dir); /* make the directory */
} else {
execle("/bin/sh", "sh", "-i", (char *) 0, environ);
execle("/usr/bin/sh", "sh", "-i", (char *) 0, environ);
error(FATAL, "cannot execute shell to ask for new diskette", "", "");
}
}
void usage()
{
fprintf(stderr, "Usage: %s [-djmnorstvz] dir1 dir2\n", pname);
exit(2);
}
void error(int type, char *s1, char *s2, char *s3)
{
fprintf(stderr, "%s: %s%s%s\n", pname, s1, s2, s3);
if (type == NONFATAL)
return;
else
exit(type);
}
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