/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2009-2018. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* %CopyrightEnd%
*/
/*
* This is a C version of the erl Bourne shell script
*/
#include "etc_common.h"
#define BOOL int
#define TRUE 1
#define FALSE 0
#define PATHSEP ":"
#define DIRSEP "/"
#define DIRSEPCHAR '/'
static void
error(char* format, ...)
{
char sbuf[1024];
va_list ap;
va_start(ap, format);
vsprintf(sbuf, format, ap);
va_end(ap);
fprintf(stderr, "erl: %s\n", sbuf);
exit(1);
}
/*
* Variables.
*/
/*
* Manage memory
*/
static void *
emalloc(size_t size)
{
void *p = malloc(size);
if (p == NULL)
error("Insufficient memory");
return p;
}
/*
static void *
erealloc(void *p, size_t size)
{
void *res = realloc(p, size);
if (res == NULL)
error("Insufficient memory");
return res;
}
*/
static void
efree(void *p)
{
free(p);
}
static char*
strsave(char* string)
{
char* p = emalloc(strlen(string)+1);
strcpy(p, string);
return p;
}
/*
* Manage environment variables
*/
static char *
get_env(char *key)
{
return getenv(key);
}
static void
set_env(char *key, char *value)
{
size_t size = strlen(key) + 1 + strlen(value) + 1;
char *str = emalloc(size);
sprintf(str, "%s=%s", key, value);
if (putenv(str) != 0)
error("putenv(\"%s\") failed!", str);
#ifdef HAVE_COPYING_PUTENV
efree(str);
#endif
}
// /* A realpath look alike */
// static char *
// follow_symlinks(const char *path, char *resolved_path)
// {
// char tmp[PATH_MAX];
// int len;
//
// strcpy(resolved_path, path);
//
// for (;;) {
// len = readlink(resolved_path, tmp, PATH_MAX);
//
// if (len == -1) {
// if (errno == EINVAL) {
// /* Not a symbolic link. use the original name */
// break;
// } else {
// return NULL;
// }
// } else {
// tmp[len] = '\0';
// strcpy(resolved_path, tmp);
// }
// }
//
// return resolved_path;
// }
/*
* Find absolute path to this program
*/
static char *
find_prog(char *origpath)
{
char relpath[PATH_MAX];
char abspath[PATH_MAX];
strcpy(relpath, origpath);
if (strstr(relpath, DIRSEP) == NULL) {
/* Just a base name */
char *envpath;
envpath = get_env("PATH");
if (envpath) {
/* Try to find the executable in the path */
char dir[PATH_MAX];
char *beg = envpath;
char *end;
int sz;
DIR *dp; /* Pointer to directory structure. */
struct dirent* dirp; /* Pointer to directory entry. */
BOOL look_for_sep = TRUE;
while (look_for_sep) {
end = strstr(beg, PATHSEP);
if (end != NULL) {
sz = end - beg;
strncpy(dir, beg, sz);
dir[sz] = '\0';
} else {
sz = strlen(beg);
strcpy(dir, beg);
look_for_sep = FALSE;
}
beg = end + 1;
dp = opendir(dir);
if (dp != NULL) {
while (TRUE) {
dirp = readdir(dp);
if (dirp == NULL) {
closedir(dp);
/* Try next directory in path */
break;
}
if (strcmp(origpath, dirp->d_name) == 0) {
/* Wow. We found the executable. */
strcpy(relpath, dir);
strcat(relpath, DIRSEP);
strcat(relpath, dirp->d_name);
closedir(dp);
look_for_sep = FALSE;
break;
}
}
}
}
}
}
if (!realpath(relpath, abspath)) {
error("Cannot determine real path to erl");
}
return strdup(abspath);
}
/*
* Find bindir
*/
static void
copy_latest_vsn(char *latest_vsn, char *next_vsn)
{
char *lp;
char *np;
BOOL greater;
/* Find vsn */
for (lp = latest_vsn+strlen(latest_vsn)-1 ;lp > latest_vsn && *lp != DIRSEPCHAR; --lp)
;
/* lp =+ length("erts-"); */
for (np = next_vsn+strlen(next_vsn)-1 ;np > next_vsn && *np != DIRSEPCHAR; --np)
;
/* np =+ length("erts-"); */
while (TRUE) {
if (*lp != *np) {
if (*np > *lp) {
greater = TRUE;
} else {
greater = FALSE;
}
/* Find next dot or eos */
while (*lp != '\0' && *np != '\0') {
lp++;
np++;
if (*np == '.' && *lp == '.') {
break;
}
if (*np == '\0' && *lp == '\0') {
break;
}
if (*lp == '.' || *lp == '\0') {
greater = TRUE;
}
if (*np == '.' || *np == '\0') {
greater = FALSE;
}
}
if (greater) {
strcpy(latest_vsn, next_vsn);
}
return;
}
++lp;
++np;
}
}
static char *
find_erts_vsn(char *erl_top)
{
/* List install dir and look for latest erts-vsn */
DIR *dp; /* Pointer to directory structure. */
struct dirent* dirp; /* Pointer to directory entry. */
char latest_vsn[PATH_MAX]; /* Latest erts-vsn directory name. */
dp = opendir(erl_top);
if (dp == NULL) {
return NULL;
}
latest_vsn[0] = '\0';
for (;;) {
dirp = readdir(dp);
if (dirp == NULL) {
closedir(dp);
break;
}
if (strncmp("erts-", dirp->d_name, 5) == 0) {
copy_latest_vsn(latest_vsn, dirp->d_name);
}
}
if (latest_vsn[0] == '\0') {
return NULL;
} else {
char *p = malloc((strlen(erl_top)+1+strlen(latest_vsn)+4+1)*sizeof(char));
strcpy(p,erl_top);
strcat(p,DIRSEP);
strcat(p,latest_vsn);
strcat(p,DIRSEP);
strcat(p,"bin");
return p;
}
}
static char *
find_bindir(char *erlpath)
{
/* Assume that the path to erl is absolute and
* that it is not a symbolic link*/
char *p;
char *p2;
char buffer[PATH_MAX];
strcpy(buffer, erlpath);
/* Chop of base name*/
for (p = buffer+strlen(buffer)-1 ;p >= buffer && *p != DIRSEPCHAR; --p)
;
*p = '\0';
p--;
/* Check if dir path is like ...\buffer\erts-vsn\bin */
for (;p >= buffer && *p != DIRSEPCHAR; --p)
;
p--;
for (p2 = p;p2 >= buffer && *p2 != DIRSEPCHAR; --p2)
;
p2++;
if (strncmp(p2, "erts-", 5) == 0) {
p = strsave(buffer);
return p;
}
/* Assume that dir path is like ...\buffer\bin */
*++p ='\0'; /* chop off bin dir */
p = find_erts_vsn(buffer);
if (p == NULL) {
return strsave(buffer);
} else {
return p;
}
}
/*
* main
*/
int
main(int argc, char **argv)
{
char *p;
char *abspath;
char *bindir; /* Location of executables. */
char rootdir[PATH_MAX]; /* Root location of Erlang installation. */
char progname[PATH_MAX]; /* Name of this program. */
char erlexec[PATH_MAX]; /* Path to erlexec */
/* Determine progname */
abspath = find_prog(argv[0]);
strcpy(progname, abspath);
for (p = progname+strlen(progname)-1;p >= progname && *p != '/'; --p)
;
/* Determine bindir */
bindir = find_bindir(abspath);
/* Determine rootdir */
strcpy(rootdir, bindir);
for (p = rootdir+strlen(rootdir)-1;p >= rootdir && *p != '/'; --p)
;
p--;
for (;p >= rootdir && *p != '/'; --p)
;
*p ='\0';
/* Update environment */
set_env("EMU", "beam");
set_env("PROGNAME", progname);
set_env("BINDIR", bindir);
set_env("ROOTDIR", rootdir);
/* Invoke erlexec */
strcpy(erlexec, bindir);
strcat(erlexec, DIRSEP);
strcat(erlexec, "erlexec");
efree(abspath);
efree(bindir);
execvp(erlexec, argv);
error("Error %d executing \'%s\'.", errno, erlexec);
return 2;
}
