source: MondoRescue/trunk/mondo/src/lib/mr_str.c@ 979

/*
 * $Id$
 *
 * New generation of string handling functions safe from a memory management point of view 
 * Developped by Andree Leidenfrost
 */

#include <stdio.h>
#include <string.h>
 
/**
 * Safe alternative to standard function strok()
 * Build a partition name from a drive and a partition number.
 * @param instr
 * @param delims
 * @param lastpos
 * @return @p
 * @note this function allocates memory that needs to be freed by caller
 **/
char *mr_strtok(char *instr, const char *delims, int *lastpos)
{

    char *token = NULL;
    char *strptr = NULL;
    size_t pos1 = 0;
    size_t pos2 = 0;

    if (strlen(instr) <= *lastpos) {
        *lastpos = 0;
        return token;
    }

    strptr = instr + *lastpos;
    pos2 = strspn(strptr, delims);
    strptr += pos2;
    pos1 = strcspn(strptr, delims);
    token = malloc(sizeof(*token) * (pos1 + 1));
    strncpy(token, strptr, pos1);
    token[pos1] = '\0';
    *lastpos = *lastpos + pos1 + pos2 + 1;

    return token;
}


/**
 * Returns the string fed to it 'inptr' with all characters to escape given
 * in 'toesc' prepended by escaping character 'escchr'.
 * (Prepare strings for use in system() or popen() with this function.)
 * @param instr
 * @param toesc
 * @param escchr
 * @note this function allocates memory that needs to be freed by caller
 **/
char *mr_stresc(char *instr, char *toesc, const char escchr)
{

    char *inptr = NULL;
    char *retstr = NULL;
    char *retptr = NULL;
    char *escptr = NULL;
    int cnt = 0;

    inptr = instr;

    // Count how many characters need escaping.
    while (*inptr != '\0') {
        escptr = toesc;
        while (*escptr != '\0') {
            if (*inptr == *escptr) {
                // Found it, skip the rest.
                cnt++;
                inptr++;
                break;
            }
            inptr++;
            escptr++;
        }
    }
    inptr = instr;

    retstr = (char *) malloc(strlen(inptr) + cnt + 1);
    retptr = retstr;

    // Prepend specified characters with escape character.
    while (*inptr != '\0') {
        escptr = toesc;
        while (*escptr != '\0') {
            if (*inptr == *escptr) {
                // Found it, skip the rest.
                *retptr = escchr;
                retptr++;
                break;
            }
            escptr++;
        }
        *retptr = *inptr;
        retptr++;
        inptr++;
    }
    *retptr = '\0';

    return retstr;
}