at_tok.c

/* //device/system/reference-ril/at_tok.c
**
** Copyright 2006, The Android Open Source Project
**
** 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.
*/

#include "at_tok.h"
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <stdarg.h>

/**
 * Starts tokenizing an AT response string
 * returns -1 if this is not a valid response string, 0 on success.
 * updates *p_cur with current position
 */
int at_tok_start(char **p_cur)
{
    if (*p_cur == NULL) {
        return -1;
    }

    // skip prefix
    // consume "^[^:]:"

    *p_cur = strchr(*p_cur, ':');

    if (*p_cur == NULL) {
        return -1;
    }

    (*p_cur)++;

    return 0;
}

static void skipWhiteSpace(char **p_cur)
{
    if (*p_cur == NULL) return;

    while (**p_cur != '\0' && isspace(**p_cur)) {
        (*p_cur)++;
    }
}

static void skipNextComma(char **p_cur)
{
    if (*p_cur == NULL) return;

    while (**p_cur != '\0' && **p_cur != ',') {
        (*p_cur)++;
    }

    if (**p_cur == ',') {
        (*p_cur)++;
    }
}

static char * nextTok(char **p_cur)
{
    char *ret = NULL;

    skipWhiteSpace(p_cur);

    if (*p_cur == NULL) {
        ret = NULL;
    } else if (**p_cur == '"') {
        (*p_cur)++;
        ret = strsep(p_cur, "\"");
        skipNextComma(p_cur);
    } else {
        ret = strsep(p_cur, ",");
    }

    return ret;
}


/**
 * Parses the next integer in the AT response line and places it in *p_out
 * returns 0 on success and -1 on fail
 * updates *p_cur
 * "base" is the same as the base param in strtol
 */

static int at_tok_nextint_base(char **p_cur, int *p_out, int base, int  uns)
{
    char *ret;

    if (*p_cur == NULL) {
        return -1;
    }

    ret = nextTok(p_cur);

    if (ret == NULL) {
        return -1;
    } else {
        long l;
        char *end;

        if (uns)
            l = strtoul(ret, &end, base);
        else
            l = strtol(ret, &end, base);

        *p_out = (int)l;

        if (end == ret) {
            return -1;
        }
    }

    return 0;
}

/**
 * Parses the next base 10 integer in the AT response line
 * and places it in *p_out
 * returns 0 on success and -1 on fail
 * updates *p_cur
 */
int at_tok_nextint(char **p_cur, int *p_out)
{
    return at_tok_nextint_base(p_cur, p_out, 10, 0);
}

/**
 * Parses the next base 16 integer in the AT response line
 * and places it in *p_out
 * returns 0 on success and -1 on fail
 * updates *p_cur
 */
int at_tok_nexthexint(char **p_cur, int *p_out)
{
    return at_tok_nextint_base(p_cur, p_out, 16, 1);
}

int at_tok_nextbool(char **p_cur, char *p_out)
{
    int ret;
    int result;

    ret = at_tok_nextint(p_cur, &result);

    if (ret < 0) {
        return -1;
    }

    // booleans should be 0 or 1
    if (!(result == 0 || result == 1)) {
        return -1;
    }

    if (p_out != NULL) {
        *p_out = (char)result;
    }

    return ret;
}

int at_tok_nextstr(char **p_cur, char **p_out)
{
    if (*p_cur == NULL) {
        return -1;
    }

    *p_out = nextTok(p_cur);

    return 0;
}

/** returns 1 on "has more tokens" and 0 if no */
int at_tok_hasmore(char **p_cur)
{
    return ! (*p_cur == NULL || **p_cur == '\0');
}

int at_tok_count(const char *in_line)
{
    int commas = 0;
    const char *p;

    if (!in_line)
        return 0;

    for (p = in_line; *p != '\0' ; p++) {
        if (*p == ',') commas++;
    }

    return commas;
}

//fmt: d ~ int, x ~ hexint, b ~ bool, s ~ str
int at_tok_scanf(const char *in_line, const char *fmt, ...)
{
    int n = 0;
    int err;
    va_list ap;
    const char *p = fmt;
    void *d;
    void *dump;
    static char s_line[1024];
    char *line = s_line;

    if (!in_line)
        return 0;

    strncpy(s_line, in_line, sizeof(s_line));

    va_start(ap, fmt);

    err = at_tok_start(&line);
    if (err < 0) goto error;

    for (; *p; p++) {
        if (*p == ',' || *p == ' ')
            continue;

        if (*p != '%') {
            goto error;
        }
        p++;

        d = va_arg(ap, void *);
        if (!d)
            d = &dump;

        if (!at_tok_hasmore(&line))
            break;
        
        if (*line == '-' && *(line + 1) == ',') {
            line += 2;
            n++;
            if (*p == 'd')
                *(int *)d = -1;
            continue;
         }

        switch(*p) {
            case 'd':
                err = at_tok_nextint(&line, (int *)d);
                if (err < 0) goto error;
           break;
            case 'x':
                err = at_tok_nexthexint(&line, (int *)d);
                if (err < 0) goto error;
            break;
            case 'b':
                err = at_tok_nextbool(&line, (char *)d);
                if (err < 0) goto error;
            break;
            case 's':
                err = at_tok_nextstr(&line, (char **)d); //if strdup(line), here return free memory to caller
                if (err < 0) goto error;
            break;
            default:
                goto error;
            break;
        }

        n++;
    }

    va_end(ap);

error:
    //free(line);
    return n;
}