source: MondoRescue/branches/2.2.10/mondo/src/common/libmondo-string.c@ 2407

/* $Id: libmondo-string.c 2405 2009-09-17 01:45:24Z bruno $ */


/**
 * @file
 * Functions for handling strings.
 */

#include "my-stuff.h"
#include "mr_mem.h"
#include "mondostructures.h"
#include "libmondo-string.h"
#include "lib-common-externs.h"
#include "libmondo-files-EXT.h"
#include "libmondo-gui-EXT.h"
#include "libmondo-tools-EXT.h"

/*@unused@*/
//static char cvsid[] = "$Id: libmondo-string.c 2405 2009-09-17 01:45:24Z bruno $";

extern int g_current_media_number;
extern long long g_tape_posK;

/* Reference to global bkpinfo */
extern struct s_bkpinfo *bkpinfo;


/**
 * @addtogroup stringGroup
 * @{
 */
/**
 * Build a partition name from a drive and a partition number.
 * @param drive The drive basename of the partition name (e.g. /dev/hda)
 * @param partno The partition number (e.g. 1)
 * @return @p partition.
 * @note If @p drive ends in a digit, then 'p' (on Linux) or 's' (on *BSD) is added before @p partno.
 */
char *build_partition_name(const char *drive, int partno)
{
    char *c = NULL;
    char *partition = NULL;

    assert_string_is_neither_NULL_nor_zerolength(drive);
    assert(partno >= 0);

    mr_asprintf(partition, "%s", drive);
    /* is this a devfs device path? */
    c = strrchr(partition, '/');
    if (c && strncmp(c, "/disc", 5) == 0) {
        /* yup it's devfs, return the "part" path */
        /* This strcpy is safe */
        strcpy(c + 1, "part");
    } else {
        if (isdigit(partition[-1])) {
            mr_strcat(partition, "%c",
#ifdef BSD
                's');
#else
                'p');
#endif
        }
    }
    mr_strcat(partition, "%d", partno);
    return(partition);
}


/**
 * Pad a string on both sides so it appears centered.
 * @param in_out The string to be center-padded (modified).
 * @param width The width of the final result.
 */
void center_string(char *in_out, int width)
{
    char scratch[MAX_STR_LEN];
    char *p;
    int i;                      /* purpose */
    int len;                    /* purpose */
    int mid;                    /* purpose */
    int x;                      /* purpose */

    assert(in_out != NULL);
    assert(width > 2);

    if (strlen(in_out) == 0) {
        return;
    }
    for (p = in_out; *p == ' '; p++);
    strcpy(scratch, p);
    strip_spaces (scratch);
    len = (int) strlen(scratch);
    mid = width / 2;
    x = mid - len / 2;
    for (i = 0; i < x; i++) {
        in_out[i] = ' ';
    }
    in_out[i] = '\0';
    strcat(in_out, scratch);
    for (i = x + len ; i < width - 1; i++) {
            in_out[i] = ' ';
        }
    in_out[i] = '\0';
}




inline void turn_wildcard_chars_into_literal_chars(char *sout, char *sin)
{
    char *p, *q;

    for (p = sin, q = sout; *p != '\0'; *(q++) = *(p++)) {
        if (strchr("[]*?", *p)) {
            *(q++) = '\\';
        }
    }
    *q = *p;                    // for the final '\0'
}



/**
 * Add commas every third place in @p input.
 * @param input The string to commarize.
 * @return The string with commas.
 * @note The returned string points to static storage that will be overwritten with each call.
 */
char *commarize(char *input)
{
    char pos_w_commas[MAX_STR_LEN];
    static char output[MAX_STR_LEN];
    char tmp[MAX_STR_LEN];
    int j;

    assert(input != NULL);

    strcpy(tmp, input);
    if (strlen(tmp) > 6) {
        strcpy(pos_w_commas, tmp);
        j = (int) strlen(pos_w_commas);
        tmp[j - 6] = ',';
        strcpy(tmp + j - 5, pos_w_commas + j - 6);
        strcpy(pos_w_commas, tmp);
    }
    if (strlen(tmp) > 3) {
        j = (int) strlen(tmp);
        strcpy(pos_w_commas, tmp);
        pos_w_commas[j - 3] = ',';
        strcpy(pos_w_commas + j - 2, tmp + j - 3);
    } else {
        strcpy(pos_w_commas, tmp);
    }
    strcpy(output, pos_w_commas);
    return (output);
}









/**
 * Turn an entry from the RAID editor's disklist into a GUI-friendly string.
 * The format is: the device left-aligned and padded to 24 places, followed by a space and the
 * index, right-aligned and padded to eight places. The total string length
 * is exactly 33.
 * @param disklist The disklist to operate on.
 * @param lino The line number from @p disklist to convert to a string.
 * @return The string form of the disklist entry.
 * @note The returned string points to static storage and will be overwritten with each call.
 */
char *disklist_entry_to_string(struct list_of_disks *disklist, int lino)
{

    /*@ buffers ********************************************************** */
    static char output[MAX_STR_LEN];

    assert(disklist != NULL);

    sprintf(output, "%-24s %8d", disklist->el[lino].device,
            disklist->el[lino].index);
    return (output);
}





/**
 * Turn a "friendly" sizestring into a number of megabytes.
 * Supports the suffixes 'k'/'K', 'm'/'M', and 'g'/'G'. Calls
 * fatal_error() if an unknown suffix is encountered.
 * @param incoming The sizestring to convert (e.g. "40m", "2g").
 * @return The size in megabytes.
 */
long friendly_sizestr_to_sizelong(char *incoming)
{
    long outval;
    int i;
    char *tmp1 = NULL;
    char ch;

    assert_string_is_neither_NULL_nor_zerolength(incoming);

    if (!incoming[0]) {
        return (0);
    }
    if (strchr(incoming, '.')) {
        fatal_error("Please use integers only. No decimal points.");
    }

    mr_asprintf(tmp1, "%s", incoming);
    i = (int) strlen(tmp1);
    if (tmp1[i - 1] == 'B' || tmp1[i - 1] == 'b') {
        tmp1[i - 1] = '\0';
    }
    for (i = 0; i < (int) strlen(tmp1) && isdigit(tmp1[i]); i++);
    ch = tmp1[i];
    tmp1[i] = '\0';
    outval = atol(tmp1);
    paranoid_free(tmp1);

    if (ch == 'g' || ch == 'G') {
        outval = outval * 1024;
    } else if (ch == 'k' || ch == 'K') {
        outval = outval / 1024;
    } else if (ch == 't' || ch == 'T')  // terabyte
    {
        outval *= 1048576;
    } else if (ch == 'Y' || ch == 'y')  // yottabyte - the biggest measure in the info file
    {
        log_it
            ("Oh my gosh. You actually think a YOTTABYTE will get you anywhere? What're you going to do with 1,208,925,819,614,629,174,706,176 bytes of data?!?!");
        popup_and_OK
            ("That sizespec is more than 1,208,925,819,614,629,174,706,176 bytes. You have a shocking amount of data. Please send a screenshot to the list :-)");
        fatal_error("Integer overflow.");
    } else if (ch != 'm' && ch != 'M') {
        mr_asprintf(tmp1, "Re: parameter '%s' - bad multiplier ('%c')", incoming, ch);
        fatal_error(tmp1);
    }
    return (outval);
}



/**
 * Add spaces to the right of @p incoming to make it @p width characters wide.
 * @param incoming The string to left-pad.
 * @param width The width to pad it to.
 * @return The left-padded string.
 * @note The returned string points to static storage that will be overwritten with each call.
 * @bug Why does center_string() modify its argument but leftpad_string() returns a modified copy?
 */
char *leftpad_string(char *incoming, int width)
{
    /*@ buffers ***************************************************** */
    static char output[MAX_STR_LEN];

    /*@ ints ******************************************************** */
    int i;

    /*@ end vars **************************************************** */
    assert(incoming != NULL);
    assert(width > 2);

    strcpy(output, incoming);
    for (i = (int) strlen(output); i < width; i++) {
        output[i] = ' ';
    }
    output[i] = '\0';
    return (output);
}



/**
 * Turn a marker byte (e.g. BLK_START_OF_BACKUP) into a string (e.g. "BLK_START_OF_BACKUP").
 * Unknown markers are identified as "BLK_UNKNOWN (%d)" where %d is the decimal value.
 * @param marker The marker byte to stringify.
 * @return @p marker as a string.
 * @note The returned string points to static storage that will be overwritten with each call.
 */
char *marker_to_string(int marker)
{
    /*@ buffer ****************************************************** */
    static char outstr[MAX_STR_LEN];


    /*@ end vars *************************************************** */

    switch (marker) {
    case BLK_START_OF_BACKUP:
        strcpy(outstr, "BLK_START_OF_BACKUP");
        break;
    case BLK_START_OF_TAPE:
        strcpy(outstr, "BLK_START_OF_TAPE");
        break;
    case BLK_START_AN_AFIO_OR_SLICE:
        strcpy(outstr, "BLK_START_AN_AFIO_OR_SLICE");
        break;
    case BLK_STOP_AN_AFIO_OR_SLICE:
        strcpy(outstr, "BLK_STOP_AN_AFIO_OR_SLICE");
        break;
    case BLK_START_AFIOBALLS:
        strcpy(outstr, "BLK_START_AFIOBALLS");
        break;
    case BLK_STOP_AFIOBALLS:
        strcpy(outstr, "BLK_STOP_AFIOBALLS");
        break;
    case BLK_STOP_BIGGIEFILES:
        strcpy(outstr, "BLK_STOP_BIGGIEFILES");
        break;
    case BLK_START_A_NORMBIGGIE:
        strcpy(outstr, "BLK_START_A_NORMBIGGIE");
        break;
    case BLK_START_A_PIHBIGGIE:
        strcpy(outstr, "BLK_START_A_PIHBIGGIE");
        break;
    case BLK_START_EXTENDED_ATTRIBUTES:
        strcpy(outstr, "BLK_START_EXTENDED_ATTRIBUTES");
        break;
    case BLK_STOP_EXTENDED_ATTRIBUTES:
        strcpy(outstr, "BLK_STOP_EXTENDED_ATTRIBUTES");
        break;
    case BLK_START_EXAT_FILE:
        strcpy(outstr, "BLK_START_EXAT_FILE");
        break;
    case BLK_STOP_EXAT_FILE:
        strcpy(outstr, "BLK_STOP_EXAT_FILE");
        break;
    case BLK_START_BIGGIEFILES:
        strcpy(outstr, "BLK_START_BIGGIEFILES");
        break;
    case BLK_STOP_A_BIGGIE:
        strcpy(outstr, "BLK_STOP_A_BIGGIE");
        break;
    case BLK_END_OF_TAPE:
        strcpy(outstr, "BLK_END_OF_TAPE");
        break;
    case BLK_END_OF_BACKUP:
        strcpy(outstr, "BLK_END_OF_BACKUP");
        break;
    case BLK_ABORTED_BACKUP:
        strcpy(outstr, "BLK_ABORTED_BACKUP");
        break;
    case BLK_START_FILE:
        strcpy(outstr, "BLK_START_FILE");
        break;
    case BLK_STOP_FILE:
        strcpy(outstr, "BLK_STOP_FILE");
        break;
    default:
        sprintf(outstr, "BLK_UNKNOWN (%d)", marker);
        break;
    }
    return (outstr);
}




/**
 * Turn a line from the mountlist into a GUI-friendly string.
 * The format is as follows: the left-aligned @p device field padded to 24 places,
 * a space, the left-aligned @p mountpoint field again padded to 24 places, a space,
 * the left-aligned @p format field padded to 10 places, a space, and the right-aligned
 * @p size field (in MB) padded to 8 places. The total string length is exactly 69.
 * @param mountlist The mountlist to operate on.
 * @param lino The line number in @p mountlist to stringify.
 * @return The string form of <tt>mountlist</tt>-\>el[<tt>lino</tt>].
 * @note The returned string points to static storage and will be overwritten with each call.
 */
char *mountlist_entry_to_string(struct mountlist_itself *mountlist,
                                int lino)
{

    /*@ buffer *********************************************************** */
    static char output[MAX_STR_LEN];

    assert(mountlist != NULL);

    sprintf(output, "%-24s %-24s %-10s %8lld", mountlist->el[lino].device,
            mountlist->el[lino].mountpoint, mountlist->el[lino].format,
            mountlist->el[lino].size / 1024L);
    return (output);
}






/**
 * Generate a friendly string containing "X blah blah disk(s)"
 * @param noof_disks The number of disks (the X).
 * @param label The "blah blah" part in the middle. If you leave this blank
 * there will be a weird double space in the middle, so pass *something*.
 * @return The string containing "X blah blah disk(s)".
 * @note The returned string points to static storage and will be overwritten with each call.
 */
char *number_of_disks_as_string(int noof_disks, char *label)
{

    /*@ buffers ********************************************************* */
    char *output = NULL;

    /*@ char     ******************************************************** */
    char p;

    assert(label != NULL);

    if (noof_disks > 1) {
        p = 's';
    } else {
        p = ' ';
    }
    mr_asprintf(output, "%d %s disk%c", noof_disks, label, p);
    while (strlen(output) < 14) {
        mr_strcat(output, " ");
    }
    return (output);
}



/**
 * Change @p i into a friendly string. If @p i is \<= 10 then write out the
 * number (e.g. "one", "two", ..., "nine", "ten", "11", ...).
 * @param i The number to stringify.
 * @return The string form of @p i.
 * @note The returned value points to static strorage that will be overwritten with each call.
 */
char *number_to_text(int i)
{

    /*@ buffers ***************************************************** */
    static char output[MAX_STR_LEN];


    /*@ end vars *************************************************** */

    switch (i) {
    case 0:
        strcpy(output, "zero");
        break;
    case 1:
        strcpy(output, "one");
        break;
    case 2:
        strcpy(output, "two");
        break;
    case 3:
        strcpy(output, "three");
        break;
    case 4:
        strcpy(output, "four");
        break;
    case 5:
        strcpy(output, "five");
        break;
    case 6:
        strcpy(output, "six");
        break;
    case 7:
        strcpy(output, "seven");
        break;
    case 8:
        strcpy(output, "eight");
        break;
    case 9:
        strcpy(output, "nine");
    case 10:
        strcpy(output, "ten");
    default:
        sprintf(output, "%d", i);
    }
    return (output);
}




/**
 * Replace all occurences of @p token with @p value while copying @p ip to @p output.
 * @param ip The input string containing zero or more <tt>token</tt>s. The string will be altered by this function
 * @param output The output string written with the <tt>token</tt>s replaced by @p value.
 * @param token The token to be relaced with @p value.
 * @param value The value to replace @p token.
 */
char *resolve_naff_tokens(char *ip, char *value, char *token)
{
    /*@ buffers *** */
    char *output = NULL;

    /*@ pointers * */
    char *p = NULL; /* points to token to modify */
    char *q = NULL; /* points to start of string/new string */

    assert_string_is_neither_NULL_nor_zerolength(token);
    assert(value != NULL);

    q = ip;
    while ((p = strstr(q, token)) != NULL) {
        *p = '\0';
        if (output) {
            mr_strcat(output, "%s%s", q, value);
        } else {
            mr_asprintf(output, "%s%s", q, value);
        }
        p+= strlen(token);
        q = p;
    }
    if (output) {
        mr_strcat(output, "%s", q);
    } else {
        /* just in case the token doesn't appear in string at all */
        mr_asprintf(output, "%s", q);
    }
    return(output);
}





/**
 * Generate the filename of slice @p sliceno of biggiefile @p bigfileno
 * in @p path with suffix @p s. The format is as follows: @p path, followed
 * by "/slice-" and @p bigfileno zero-padded to 7 places, followed by
 * a dot and @p sliceno zero-padded to 5 places, followed by ".dat" and the
 * suffix. The string is a minimum of 24 characters long.
 * @param bigfileno The biggiefile number. Starts from 0.
 * @param sliceno The slice number of biggiefile @p bigfileno. 0 is a "header"
 * slice (no suffix) containing the biggiestruct, then are the compressed
 * slices, then an empty uncompressed "trailer" slice.
 * @param path The path to append (with a / in the middle) to the slice filename.
 * @param s If not "" then add a "." and this to the end.
 * @return The slice filename.
 * @note The returned value points to static storage and will be overwritten with each call.
 */
char *slice_fname(long bigfileno, long sliceno, char *path, char *s)
{

    /*@ buffers **************************************************** */
    static char output[MAX_STR_LEN];
    char *suffix = NULL;

    /*@ end vars *************************************************** */

    assert_string_is_neither_NULL_nor_zerolength(path);
    if (s[0] != '\0') {
        mr_asprintf(suffix, ".%s", s);
    } else {
        mr_asprintf(suffix, "");
    }
    sprintf(output, "%s/slice-%07ld.%05ld.dat%s", path, bigfileno, sliceno, suffix);
    mr_free(suffix);
    return (output);
}


/**
 * Generate a spinning symbol based on integer @p i.
 * The symbol rotates through the characters / - \ | to form an ASCII "spinner"
 * if successively written to the same location on screen.
 * @param i The amount of progress or whatever else to use to determine the character
 * for this iteration of the spinner.
 * @return The character for this iteration.
 */
int special_dot_char(int i)
{
    switch (i % 4) {
    case 0:
        return ('/');
    case 1:
        return ('-');
    case 2:
        return ('\\');
    case 3:
        return ('|');
    default:
        return ('.');
    }
    return ('.');
}


/**
 * Compare @p stringA and @p stringB. This uses an ASCII sort for everything
 * up to the digits on the end but a numerical sort for the digits on the end.
 * @param stringA The first string to compare.
 * @param stringB The second string to compare.
 * @return The same as strcmp() - <0 if A<B, 0 if A=B, >0 if A>B.
 * @note This function only does a numerical sort on the @e last set of numbers. If
 * there are any in the middle those will be sorted ASCIIbetically.
 */
int strcmp_inc_numbers(char *stringA, char *stringB)
{
    /*@ int ********************************************************* */
    int i;
    int start_of_numbers_in_A;
    int start_of_numbers_in_B;
    int res;

    /*@ long ******************************************************* */
    long numA;
    long numB;

    /*@ end vars *************************************************** */
    assert(stringA != NULL);
    assert(stringB != NULL);

    if (strlen(stringA) == strlen(stringB)) {
        return (strcmp(stringA, stringB));
    }
    for (i = (int) strlen(stringA); i > 0 && isdigit(stringA[i - 1]); i--);
    if (i == (int) strlen(stringA)) {
        return (strcmp(stringA, stringB));
    }
    start_of_numbers_in_A = i;
    for (i = (int) strlen(stringB); i > 0 && isdigit(stringB[i - 1]); i--);
    if (i == (int) strlen(stringB)) {
        return (strcmp(stringA, stringB));
    }
    start_of_numbers_in_B = i;
    if (start_of_numbers_in_A != start_of_numbers_in_B) {
        return (strcmp(stringA, stringB));
    }
    res = strncmp(stringA, stringB, (size_t) i);
    if (res) {
        return (res);
    }
    numA = atol(stringA + start_of_numbers_in_A);
    numB = atol(stringB + start_of_numbers_in_B);
    return ((int) (numA - numB));
}



/**
 * Strip excess baggage from @p input, which should be a line from afio.
 * For now this copies the whole line unless it finds a set of quotes, in which case
 * it copies their contents only.
 * @param input The input line (presumably from afio).
 * @return The stripped line.
 * @note The returned string points to static storage that will be overwritten with each call.
 */
char *strip_afio_output_line(char *input)
{
    /*@ buffer ****************************************************** */
    static char output[MAX_STR_LEN];

    /*@ pointers **************************************************** */
    char *p;
    char *q;
    /*@ end vars *************************************************** */

    assert(input != NULL);
    strcpy(output, input);
    p = strchr(input, '\"');
    if (p) {
        q = strchr(++p, '\"');
        if (q) {
            strcpy(output, p);
            *(strchr(output, '\"')) = '\0';
        }
    }
    return (output);
}



/**
 * Remove all characters whose ASCII value is less than or equal to 32
 * (spaces and control characters) from both sides of @p in_out.
 * @param in_out The string to strip spaces/control characters from (modified).
 */
void strip_spaces(char *in_out)
{
    /*@ buffers ***************************************************** */
    char *tmp;

    /*@ pointers **************************************************** */
    char *p;

    /*@ int ******************************************************** */
    int i;
    int original_incoming_length;

    /*@ end vars *************************************************** */

    assert(in_out != NULL);
    malloc_string(tmp);
    original_incoming_length = (int) strlen(in_out);
    for (i = 0; in_out[i] <= ' ' && i < (int) strlen(in_out); i++);
    strcpy(tmp, in_out + i);
    for (i = (int) strlen(tmp); i > 0 && tmp[i - 1] <= 32; i--);
    tmp[i] = '\0';
    for (i = 0; i < original_incoming_length && MAX_STR_LEN; i++) {
        in_out[i] = ' ';
    }
    in_out[i] = '\0';
    i = 0;
    p = tmp;
    while (*p != '\0') {
        in_out[i] = *(p++);
        in_out[i + 1] = '\0';
        if (in_out[i] < 32 && i > 0) {
            if (in_out[i] == 8) {
                i--;
            } else if (in_out[i] == 9) {
                in_out[i++] = ' ';
            } else if (in_out[i] == '\r')   // added 1st October 2003 -- FIXME
            {
                strcpy(tmp, in_out + i);
                strcpy(in_out, tmp);
                i = -1;
                continue;
            } else if (in_out[i] == '\t') {
                for (i++; i % 5; i++);
            } else if (in_out[i] >= 10 && in_out[i] <= 13) {
                break;
            } else {
                i--;
            }
        } else {
            i++;
        }
    }
    in_out[i] = '\0';
    paranoid_free(tmp);
}


/**
 * If there are double quotes "" around @p incoming then remove them.
 * This does not affect other quotes that may be embedded within the string.
 * @param incoming The string to trim quotes from (modified).
 * @return @p incoming.
 */
char *trim_empty_quotes(char *incoming)
{
    /*@ buffer ****************************************************** */
    static char outgoing[MAX_STR_LEN];

    /*@ end vars *************************************************** */
    assert(incoming != NULL);

    if (incoming[0] == '\"' && incoming[strlen(incoming) - 1] == '\"') {
        strcpy(outgoing, incoming + 1);
        outgoing[strlen(outgoing) - 1] = '\0';
    } else {
        strcpy(outgoing, incoming);
    }
    return (outgoing);
}




/**
 * Remove any partition info from @p partition, leaving just the drive name.
 * @param partition The partition name soon-to-become drive name. (modified)
 * @return @p partition.
 */
char *truncate_to_drive_name(char *partition)
{
    int i = strlen(partition) - 1;
    char *c;
    char *trunc = NULL;

    assert_string_is_neither_NULL_nor_zerolength(partition);
    mr_asprintf(trunc, "%s", partition);

#ifdef __FreeBSD__

    if (islower(trunc[i]))  // BSD subpartition
        i--;
    if (trunc[i-1] == 's') {
        while (isdigit(trunc[i]))
            i--;
        i--;
    }
    trunc[i+1] = '\0';

#else

    /* first see if it's a devfs style device */
    c = strrchr(trunc, '/');
    if (c && strncmp(c, "/part", 5) == 0) {
        /* yup it's devfs, return the "disc" path */
        strcpy(c + 1, "disc");
        return trunc;
    }
    /* then see if it's a dm style device */
    if (c && strncmp(c, "/dm-", 4) == 0) {
        /* yup it's dm, return the full path */
        return trunc;
    }


    for (i = strlen(trunc); isdigit(trunc[i-1]); i--)
        continue;
    if (trunc[i-1] == 'p' && isdigit(trunc[i-2])) {
        i--;
    } else {
        /* Some full devices like this /dev/mapper/mpath0
           /dev/cciss/c0d0 may be used as partition names */
        if ((strstr(trunc,"/dev/mapper/mpath") != NULL) ||
            (strstr(trunc,"/dev/cciss/c") != NULL) ||
            (strstr(trunc,"/dev/rd/") != NULL)) {
                return trunc;
            }
    }
    trunc[i] = '\0';

#endif

    return trunc;
}





/**
 * Turn a RAID level number (-1 to 5) into a friendly string. The string
 * is either "Linear RAID" for -1, or " RAID %-2d " (%d = @p raid_level)
 * for anything else.
 * @param raid_level The RAID level to stringify.
 * @return The string form of @p raid_level.
 * @note The returned value points to static storage that will be overwritten with each call.
 */
char *turn_raid_level_number_to_string(int raid_level)
{

    /*@ buffer ********************************************************** */
    static char output[MAX_STR_LEN];



    if (raid_level >= 0) {
        sprintf(output, " RAID %-2d ", raid_level);
    } else {
        sprintf(output, "Linear RAID");
    }
    return (output);
}









/**
 * Determine the severity (1-3, 1 being low) of the fact that
 * @p fn changed in the live filesystem (verify/compare).
 * @param fn The filename that changed.
 * @param out_reason If non-NULL, a descriptive reason for the difference will be copied here.
 * @return The severity (1-3).
 */
int severity_of_difference(char *fn, char *out_reason) {

    int sev;
    char *reason = NULL;
    char *filename = NULL;

    // out_reason might be null on purpose, so don't bomb if it is :) OK?
    assert_string_is_neither_NULL_nor_zerolength(fn);
    if (!strncmp(fn, MNT_RESTORING, strlen(MNT_RESTORING))) {
        mr_asprintf(filename, "%s", fn + strlen(MNT_RESTORING));
    } else if (fn[0] != '/') {
        mr_asprintf(filename, "/%s", fn);
    } else {
        mr_asprintf(filename, "%s", fn);
    }

    sev = 3;
    mr_asprintf(reason, "Changed since backup. Consider running a differential backup in a day or two.");

    if (!strncmp(filename, "/var/", 5)) {
        sev = 2;
        mr_free(reason);
        mr_asprintf(reason, "/var's contents will change regularly, inevitably.");
    }
    if (!strncmp(filename, "/home", 5)) {
        sev = 2;
        mr_free(reason);
        mr_asprintf(reason, "It's in your /home directory. Therefore, it is important.");
    }
    if (!strncmp(filename, "/usr/", 5)) {
        sev = 3;
        mr_free(reason);
        mr_asprintf(reason, "You may have installed/removed software during the backup.");
    }
    if (!strncmp(filename, "/etc/", 5)) {
        sev = 3;
        mr_free(reason);
        mr_asprintf(reason, "Do not edit config files while backing up your PC.");
    }
    if (!strcmp(filename, "/etc/adjtime")
        || !strcmp(filename, "/etc/mtab")) {
        sev = 1;
        mr_free(reason);
        mr_asprintf(reason, "This file changes all the time. It's OK.");
    }
    if (!strncmp(filename, "/root/", 6)) {
        sev = 3;
        mr_free(reason);
        mr_asprintf(reason, "Were you compiling/editing something in /root?");
    }
    if (!strncmp(filename, "/root/.", 7)) {
        sev = 2;
        mr_free(reason);
        mr_asprintf(reason, "Temp or 'dot' files changed in /root.");
    }
    if (!strncmp(filename, "/var/lib/", 9)) {
        sev = 2;
        mr_free(reason);
        mr_asprintf(reason, "Did you add/remove software during backing?");
    }
    if (!strncmp(filename, "/var/lib/rpm", 12)) {
        sev = 3;
        mr_free(reason);
        mr_asprintf(reason, "Did you add/remove software during backing?");
    }
    if (!strncmp(filename, "/var/lib/slocate", 16)) {
        sev = 1;
        mr_free(reason);
        mr_asprintf(reason, "The 'update' daemon ran during backup. This does not affect the integrity of your backup.");
    }
    if (!strncmp(filename, "/var/log/", 9)
        || strstr(filename, "/.xsession")
        || !strcmp(filename + strlen(filename) - 4, ".log")) {
        sev = 1;
        mr_free(reason);
        mr_asprintf(reason, "Log files change frequently as the computer runs. Fret not.");
    }
    if (!strncmp(filename, "/var/spool", 10)) {
        sev = 1;
        mr_free(reason);
        mr_asprintf(reason, "Background processes or printers were active. This does not affect the integrity of your backup.");
    }
    if (!strncmp(filename, "/var/spool/mail", 10)) {
        sev = 2;
        mr_free(reason);
        mr_asprintf(reason, "Mail was sent/received during backup.");
    }
    if (filename[strlen(filename) - 1] == '~') {
        sev = 1;
        mr_free(reason);
        mr_asprintf(reason, "Backup copy of another file which was modified recently.");
    }
    if (strstr(filename, "cache")) {
        sev = 1;
        mr_free(reason);
        mr_asprintf(reason, "Part of a cache of data. Caches change from time to time. Don't worry.");
    }
    if (!strncmp(filename, "/var/run/", 9)
        || !strncmp(filename, "/var/lock", 8)
        || strstr(filename, "/.DCOPserver") || strstr(filename, "/.MCOP")
        || strstr(filename, "/.Xauthority")) {
        sev = 1;
        mr_free(reason);
        mr_asprintf(reason, "Temporary file (a lockfile, perhaps) used by software such as X or KDE to register its presence.");
    }
    if (out_reason) {
        strcpy(out_reason, reason);
    }
    mr_free(filename);
    mr_free(reason);
    return (sev);
}



/**
 * Compare the filenames in two filelist entries (s_filelist_entry*) casted
 * to void*.
 * @param va The first filelist entry, cast as a @c void pointer.
 * @param vb The second filelist entry, cast as a @c void pointer.
 * @return The return value of strcmp().
 */
int compare_two_filelist_entries(void *va, void *vb)
{
    static int res;
    struct s_filelist_entry *fa, *fb;

    assert(va != NULL);
    assert(vb != NULL);
    fa = (struct s_filelist_entry *) va;
    fb = (struct s_filelist_entry *) vb;
    res = strcmp(fa->filename, fb->filename);
    return (res);
}







/**
 * Generate a line intended to be passed to update_evalcall_form(), indicating
 * the current media fill percentage (or number of kilobytes if size is not known).
 * @param bkpinfo The backup media structure. Fields used:
 * - @c bkpinfo->backup_media_type
 * - @c bkpinfo->media_size
 * - @c bkpinfo->scratchdir
 * @return The string indicating media fill.
 * @note The returned string points to static storage that will be overwritten with each call.
 */
char *percent_media_full_comment()
{
    /*@ int *********************************************** */
    int percentage;
    int j;

    /*@ buffers ******************************************* */
    char *outstr = NULL;
    char *pos_w_commas = NULL;
    char *mds = NULL;
    char *tmp = NULL;

    assert(bkpinfo != NULL);

    if (bkpinfo->media_size[g_current_media_number] <= 0) {
        mr_asprintf(tmp, "%lld", g_tape_posK);
        mr_asprintf(pos_w_commas, "%s", commarize(tmp));
        mr_free(tmp);
        mr_asprintf(outstr, "Volume %d: %s kilobytes archived so far", g_current_media_number, pos_w_commas);
        mr_free(pos_w_commas);
        return (outstr);
    }

/* update screen */
    if (IS_THIS_A_STREAMING_BACKUP(bkpinfo->backup_media_type)) {
        percentage =
            (int) (g_tape_posK / 10 /
                   bkpinfo->media_size[g_current_media_number]);
        if (percentage > 100) {
            percentage = 100;
        }
        mr_asprintf(outstr, "Volume %d: [", g_current_media_number);
    } else {
        percentage =
            (int) (space_occupied_by_cd(bkpinfo->scratchdir) * 100 / 1024 /
                   bkpinfo->media_size[g_current_media_number]);
        mds = media_descriptor_string(bkpinfo->backup_media_type);
        mr_asprintf(outstr, "%s %d: [", mds, g_current_media_number);
        mr_free(mds);
    }
    for (j = 0; j < percentage; j += 5) {
        mr_strcat(outstr, "*");
    }
    for (; j < 100; j += 5) {
        mr_strcat(outstr, ".");
    }
    mr_strcat(outstr, "] %d%% used", percentage);
    return (outstr);
}

/**
 * Get a string form of @p type_of_bkp.
 * @param type_of_bkp The backup type to stringify.
 * @return The stringification of @p type_of_bkp.
 * @note The returned string points to static storage that will be overwritten with each call.
 */
char *media_descriptor_string(t_bkptype type_of_bkp) {

    char *type_of_backup = NULL;

    switch (type_of_bkp) {
    case dvd:
        mr_asprintf(type_of_backup, "DVD");
        break;
    case cdr:
        mr_asprintf(type_of_backup, "CDR");
        break;
    case cdrw:
        mr_asprintf(type_of_backup, "CDRW");
        break;
    case tape:
        mr_asprintf(type_of_backup, "tape");
        break;
    case cdstream:
        mr_asprintf(type_of_backup, "CDR");
        break;
    case udev:
        mr_asprintf(type_of_backup, "udev");
        break;
    case iso:
        mr_asprintf(type_of_backup, "ISO");
        break;
    case netfs:
        mr_asprintf(type_of_backup, "%s", bkpinfo->netfs_proto);
        break;
    case usb:
        mr_asprintf(type_of_backup, "USB");
        break;
    default:
        mr_asprintf(type_of_backup, "ISO");
    }
    return (type_of_backup);
}