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#include <unistd.h>
#ifndef _POSIX_SOURCE
#define _POSIX_SOURCE
#endif
#include <stdio.h>
#include <stdlib.h>
#if !defined(__APPLE__)
#include <malloc.h>
#endif
#include <string.h>
#include <fcntl.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <time.h>
#include <stddef.h>
#include <errno.h>
#ifndef S_ISLNK
#define S_ISLNK(mode) (((mode) & (_S_IFMT)) == (_S_IFLNK))
#endif
#ifndef PATH_MAX
#define PATH_MAX 1024
#endif
#define progver "%s: scan/change symbolic links - v1.4.3\n\n"
static char *progname;
static int verbose = 0,
fix_links = 0,
recurse = 0,
delete = 0,
shorten = 0,
testing = 0,
single_fs = 1;
/*
* tidypath removes excess slashes and "." references from a path string
*/
static int substr(char *s, char *old, char *new) {
char *tmp = NULL;
unsigned long oldlen = strlen(old), newlen = 0;
if (NULL == strstr(s, old)) {
return 0;
}
if (new) {
newlen = strlen(new);
}
if (newlen > oldlen) {
if ((tmp = malloc(strlen(s))) == NULL) {
fprintf(stderr, "no memory\n");
exit(1);
}
}
while (NULL != (s = strstr(s, old))) {
char *p, *old_s = s;
if (new) {
if (newlen > oldlen) {
old_s = strcpy(tmp, s);
}
p = new;
while (*p) {
*s++ = *p++;
}
}
p = old_s + oldlen;
while ((*s++ = *p++));
}
if (tmp) {
free(tmp);
}
return 1;
}
static int tidy_path(char *path) {
int tidied = 0;
char *s, *p;
s = path + strlen(path) - 1;
if (s[0] != '/') { /* tmp trailing slash simplifies things */
s[1] = '/';
s[2] = '\0';
}
while (substr(path, "/./", "/")) {
tidied = 1;
}
while (substr(path, "//", "/")) {
tidied = 1;
}
while ((p = strstr(path, "/../")) != NULL) {
s = p + 3;
for (p--; p != path; p--) {
if (*p == '/') { break; }
}
if (*p != '/') { break; }
while ((*p++ = *s++));
tidied = 1;
}
if (*path == '\0') {
strcpy(path, "/");
}
p = path + strlen(path) - 1;
if (p != path && *p == '/') {
*p-- = '\0'; /* remove tmp trailing slash */
}
while (p != path && *p == '/') { /* remove any others */
*p-- = '\0';
tidied = 1;
}
while (!strncmp(path, "./", 2)) {
for (p = path, s = path + 2; (*p++ = *s++););
tidied = 1;
}
return tidied;
}
static int shorten_path(char *path, char *abspath) {
static char dir[PATH_MAX];
int shortened = 0;
char *p;
/* get rid of unnecessary "../dir" sequences */
while (abspath && strlen(abspath) > 1 && (p = strstr(path, "../"))) {
/* find innermost occurance of "../dir", and save "dir" */
int slashes = 2;
char *a, *s, *d = dir;
while ((s = strstr(p + 3, "../"))) {
++slashes;
p = s;
}
s = p + 3;
*d++ = '/';
while (*s && *s != '/') {
*d++ = *s++;
}
*d++ = '/';
*d = '\0';
if (!strcmp(dir, "//")) {
break;
}
/* note: p still points at ../dir */
if (*s != '/' || !*++s) {
break;
}
a = abspath + strlen(abspath) - 1;
while (slashes-- > 0) {
if (a <= abspath) {
goto ughh;
}
while (*--a != '/') {
if (a <= abspath) {
goto ughh;
}
}
}
if (strncmp(dir, a, strlen(dir))) {
break;
}
while ((*p++ = *s++)); /* delete the ../dir */
shortened = 1;
}
ughh:
return shortened;
}
static void fix_symlink(char *path, dev_t my_dev) {
static char lpath[PATH_MAX], new[PATH_MAX], abspath[PATH_MAX];
char *p, *np, *lp, *tail, *msg;
struct stat stbuf, lstbuf;
int fix_abs = 0, fix_messy = 0, fix_long = 0;
size_t c;
if ((c = readlink(path, lpath, sizeof(lpath))) == -1) {
perror(path);
return;
}
lpath[c] = '\0'; /* readlink does not null terminate it */
/* construct the absolute address of the link */
abspath[0] = '\0';
if (lpath[0] != '/') {
strcat(abspath, path);
c = strlen(abspath);
if ((c > 0) && (abspath[c - 1] == '/')) {
abspath[c - 1] = '\0'; /* cut trailing / */
}
if ((p = strrchr(abspath, '/')) != NULL) {
*p = '\0'; /* cut last component */
}
strcat(abspath, "/");
}
strcat(abspath, lpath);
(void) tidy_path(abspath);
/* check for various things */
if (stat(abspath, &stbuf) == -1) {
printf("dangling: %s -> %s\n", path, lpath);
if (delete) {
if (unlink(path)) {
perror(path);
} else {
printf("deleted: %s -> %s\n", path, lpath);
}
}
return;
}
if (single_fs) {
lstat(abspath, &lstbuf); /* if the above didn't fail, then this shouldn't */
}
if (single_fs && lstbuf.st_dev != my_dev) {
msg = "other_fs:";
} else if (lpath[0] == '/') {
msg = "absolute:";
fix_abs = 1;
} else if (verbose) {
msg = "relative:";
} else {
msg = NULL;
}
fix_messy = tidy_path(strcpy(new, lpath));
if (shorten) {
fix_long = shorten_path(new, path);
}
if (!fix_abs) {
if (fix_messy) {
msg = "messy: ";
} else if (fix_long) {
msg = "lengthy: ";
}
}
if (msg != NULL) {
printf("%s %s -> %s\n", msg, path, lpath);
}
if (!(fix_links || testing) || !(fix_messy || fix_abs || fix_long)) {
return;
}
if (fix_abs) {
/* convert an absolute link to relative: */
/* point tail at first part of lpath that differs from path */
/* point p at first part of path that differs from lpath */
(void) tidy_path(lpath);
tail = lp = lpath;
p = path;
while (*p && (*p == *lp)) {
if (*lp++ == '/') {
tail = lp;
while (*++p == '/');
}
}
/* now create new, with "../"s followed by tail */
np = new;
while (*p) {
if (*p++ == '/') {
*np++ = '.';
*np++ = '.';
*np++ = '/';
while (*p == '/') {
++p;
}
}
}
strcpy(np, tail);
(void) tidy_path(new);
if (shorten) {
(void) shorten_path(new, path);
}
}
shorten_path(new, path);
if (!testing) {
if (unlink(path)) {
perror(path);
return;
}
if (symlink(new, path)) {
perror(path);
return;
}
}
printf("changed: %s -> %s\n", path, new);
}
static void dirwalk(char *path, unsigned long pathlen, dev_t dev) {
char *name;
DIR *dfd;
static struct stat st;
static struct dirent *dp;
if ((dfd = opendir(path)) == NULL) {
perror(path);
return;
}
name = path + pathlen;
if (*(name - 1) != '/') {
*name++ = '/';
}
while ((dp = readdir(dfd)) != NULL) {
strcpy(name, dp->d_name);
if (strcmp(name, ".") && strcmp(name, "..")) {
if (lstat(path, &st) == -1) {
perror(path);
} else if (st.st_dev == dev) {
if (S_ISLNK(st.st_mode)) {
fix_symlink(path, dev);
} else if (recurse && S_ISDIR(st.st_mode)) {
dirwalk(path, strlen(path), dev);
}
}
}
}
closedir(dfd);
path[pathlen] = '\0';
}
static void usage_error(void) {
fprintf(stderr, progver, progname);
fprintf(stderr, "Usage:\t%s [-cdorstv] dirlist\n\n", progname);
fprintf(stderr, "Flags:"
"\t-c change absolute/messy links to relative\n"
"\t-d delete dangling links\n"
"\t-o warn about links across file systems\n"
"\t-r recurse into subdirs\n"
"\t-s shorten lengthy links (displayed in output only when -c not specified)\n"
"\t-t show what would be done by -c\n"
"\t-v verbose (show all symlinks)\n\n");
exit(1);
}
int main(int argc, char **argv) {
static char path[PATH_MAX + 2], cwd[PATH_MAX + 2];
int dircount = 0;
char c, *p;
if ((progname = (char *) strrchr(*argv, '/')) == NULL) {
progname = *argv;
} else {
progname++;
}
if (NULL == getcwd(cwd, PATH_MAX)) {
fprintf(stderr, "getcwd() failed\n");
exit(1);
}
if (!*cwd || cwd[strlen(cwd) - 1] != '/') {
strcat(cwd, "/");
}
while (--argc) {
p = *++argv;
if (*p == '-') {
if (*++p == '\0') {
usage_error();
}
while ((c = *p++)) {
if (c == 'c') { fix_links = 1;
} else if (c == 'd') { delete = 1;
} else if (c == 'o') { single_fs = 0;
} else if (c == 'r') { recurse = 1;
} else if (c == 's') { shorten = 1;
} else if (c == 't') { testing = 1;
} else if (c == 'v') { verbose = 1;
} else {
usage_error();
}
}
} else {
struct stat st;
if (*p == '/') {
*path = '\0';
} else {
strcpy(path, cwd);
}
tidy_path(strcat(path, p));
if (lstat(path, &st) == -1) {
perror(path);
} else {
dirwalk(path, strlen(path), st.st_dev);
}
++dircount;
}
}
if (dircount == 0) {
usage_error();
}
exit(0);
}
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