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/*
* (C) Copyright 2012
* Joe Hershberger, National Instruments, joe.hershberger@ni.com
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifdef USE_HOSTCC /* Eliminate "ANSI does not permit..." warnings */
#include <stdint.h>
#include <stdio.h>
#include <linux/linux_string.h>
#else
#include <common.h>
#endif
#include <env_attr.h>
#include <errno.h>
#include <linux/string.h>
#include <malloc.h>
/*
* Iterate through the whole list calling the callback for each found element.
* "attr_list" takes the form:
* attributes = [^,:\s]*
* entry = name[:attributes]
* list = entry[,list]
*/
int env_attr_walk(const char *attr_list,
int (*callback)(const char *name, const char *attributes))
{
const char *entry, *entry_end;
char *name, *attributes;
if (!attr_list)
/* list not found */
return 1;
entry = attr_list;
do {
char *entry_cpy = NULL;
entry_end = strchr(entry, ENV_ATTR_LIST_DELIM);
/* check if this is the last entry in the list */
if (entry_end == NULL) {
int entry_len = strlen(entry);
if (entry_len) {
/*
* allocate memory to copy the entry into since
* we will need to inject '\0' chars and squash
* white-space before calling the callback
*/
entry_cpy = malloc(entry_len + 1);
if (entry_cpy)
/* copy the rest of the list */
strcpy(entry_cpy, entry);
else
return -ENOMEM;
}
} else {
int entry_len = entry_end - entry;
if (entry_len) {
/*
* allocate memory to copy the entry into since
* we will need to inject '\0' chars and squash
* white-space before calling the callback
*/
entry_cpy = malloc(entry_len + 1);
if (entry_cpy) {
/* copy just this entry and null term */
strncpy(entry_cpy, entry, entry_len);
entry_cpy[entry_len] = '\0';
} else
return -ENOMEM;
}
}
/* check if there is anything to process (e.g. not ",,,") */
if (entry_cpy != NULL) {
attributes = strchr(entry_cpy, ENV_ATTR_SEP);
/* check if there is a ':' */
if (attributes != NULL) {
/* replace the ':' with '\0' to term name */
*attributes++ = '\0';
/* remove white-space from attributes */
attributes = strim(attributes);
}
/* remove white-space from name */
name = strim(entry_cpy);
/* only call the callback if there is a name */
if (strlen(name) != 0) {
int retval = 0;
retval = callback(name, attributes);
if (retval) {
free(entry_cpy);
return retval;
}
}
}
free(entry_cpy);
entry = entry_end + 1;
} while (entry_end != NULL);
return 0;
}
/*
* Search for the last matching string in another string with the option to
* start looking at a certain point (i.e. ignore anything beyond that point).
*/
static char *reverse_strstr(const char *searched, const char *search_for,
const char *searched_start)
{
char *result = NULL;
if (*search_for == '\0')
return (char *)searched;
for (;;) {
char *match = strstr(searched, search_for);
/*
* Stop looking if no new match is found or looking past the
* searched_start pointer
*/
if (match == NULL || (searched_start != NULL &&
match + strlen(search_for) > searched_start))
break;
result = match;
searched = match + 1;
}
return result;
}
/*
* Retrieve the attributes string associated with a single name in the list
* There is no protection on attributes being too small for the value
*/
int env_attr_lookup(const char *attr_list, const char *name, char *attributes)
{
const char *entry = NULL;
if (!attributes)
/* bad parameter */
return -EINVAL;
if (!attr_list)
/* list not found */
return -EINVAL;
entry = reverse_strstr(attr_list, name, NULL);
while (entry != NULL) {
const char *prevch = entry - 1;
const char *nextch = entry + strlen(name);
/* Skip spaces */
while (*prevch == ' ')
prevch--;
while (*nextch == ' ')
nextch++;
/* check for an exact match */
if ((entry == attr_list ||
*prevch == ENV_ATTR_LIST_DELIM) &&
(*nextch == ENV_ATTR_SEP ||
*nextch == ENV_ATTR_LIST_DELIM ||
*nextch == '\0'))
break;
entry = reverse_strstr(attr_list, name, entry);
}
if (entry != NULL) {
int len;
/* skip the name */
entry += strlen(name);
/* skip spaces */
while (*entry == ' ')
entry++;
if (*entry != ENV_ATTR_SEP)
len = 0;
else {
const char *delim;
static const char delims[] = {
ENV_ATTR_LIST_DELIM, ' ', '\0'};
/* skip the attr sep */
entry += 1;
/* skip spaces */
while (*entry == ' ')
entry++;
delim = strpbrk(entry, delims);
if (delim == NULL)
len = strlen(entry);
else
len = delim - entry;
memcpy(attributes, entry, len);
}
attributes[len] = '\0';
/* success */
return 0;
}
/* not found in list */
return -ENOENT;
}
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