parse_mon.c

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/* parse_mon - parse monitorcap entry */

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <grass/gis.h>
#include <grass/glocale.h>
#include <grass/raster.h>
#include <grass/monitors.h>

static FILE *monitors = NULL;
static struct MON_CAP cap;

static char *substr(char *, char *);
static int read_line(FILE *, char *, int);

struct MON_CAP *R_parse_monitorcap(int field, char *key)
{
    int rewound;
    char line[1024];
    char *p;
    char file[500];
    char *gisbase;

    gisbase = G_gisbase();

    rewound = 0;
    if (!(field == MON_NEXT || field == MON_NAME ||
          field == MON_PATH || field == MON_LINK || field == MON_CLOSE))
        return (NULL);
    if (monitors == NULL) {
        sprintf(file, "%s/etc/monitorcap", gisbase);
        if ((monitors = fopen(file, "r")) == NULL)
            G_fatal_error("Unable to open %s", file);
    }
    else {
        if (field == MON_CLOSE) {
            fclose(monitors);
            monitors = NULL;
            return (NULL);
        }
    }
    while (-1) {
        if (read_line(monitors, line, sizeof line)) {
            if (field == MON_NEXT)
                return (NULL);
            rewind(monitors);
            if (read_line(monitors, line, sizeof line) || rewound)
                return (NULL);
            rewound = -1;
        }
        cap.path = cap.comment = cap.link = cap.tty = cap.where = NULL;
        if ((cap.name = G_malloc(strlen(line) + 1)) == NULL)
            return (NULL);
        strcpy(cap.name, line);
        if ((p = substr(":", cap.name)) != NULL) {
            *p++ = '\0';
            cap.path = p;
            if ((p = substr(":", p)) != NULL) {
                *p++ = '\0';
                cap.comment = p;
                if ((p = substr(":", p)) != NULL) {
                    *p++ = '\0';
                    cap.link = p;
                    if ((p = substr(":", p)) != NULL) {
                        *p++ = '\0';
                        cap.tty = p;
                        if ((p = substr(":", p)) != NULL) {
                            *p++ = 0;
                            cap.where = p;
                            if ((p = substr("\n", p)) != NULL)
                                *p = '\0';
                        }
                    }
                }
            }
        }
        if (cap.path == NULL || cap.link == NULL || cap.where == NULL ||
            cap.tty == NULL || cap.comment == NULL)
            G_free(cap.name);
        else {
            sprintf(line, "%s/%s", gisbase, cap.path);
            cap.path = G_store(line);

            if (field == MON_NEXT ||
                (field == MON_NAME && !strcmp(key, cap.name))
                || (field == MON_PATH && !strcmp(key, cap.path))
                || (field == MON_LINK && !strcmp(key, cap.link)))
                return (&cap);
            else
                G_free(cap.name);
        }
    }
}

/* read_line - read a line, possibly continued with a "\" into a buffer */

static int read_line(FILE * file,       /* file from which to read */
                     char *line,        /* buffer in which to put it */
                     int size)
{                               /* size of buffer */
    int length, full_line, eof, done;
    char c, last_c;

    *line = '\0';
    for (length = full_line = eof = 0; !full_line && !eof;) {   /*   one entire line at a time */
        while (1) {
            eof = (fgets(line + length, size - length - 1, file) == NULL);
            if (eof)
                break;
            if (*(line + length) != '#')
                break;
        }
        length = strlen(line) - 1;
        if (*(line + length) == '\n') {
            if (*(line + length - 1) == '\\')
                --length;
            else
                full_line = -1;
        }
        else {
            if (length != -1) {
                fprintf(stderr, "error:  input line too long\n");
                full_line = -1;
                last_c = c = ' ';
                for (done = 0; !done;) {
                    if ((c = getc(file)) != EOF) {
                        if (c == '\n' && last_c != '\\')
                            done = -1;
                        else
                            last_c = c;
                    }
                    else
                        eof = done = -1;
                }
            }
        }
    }
    return (eof);
}

/* substr - find substring in a string.  returns pointer to start of */
/* substring or NULL if not found */

static char *substr(char *string, char *buffer)
{
    int start, i, found;
    char c;

    start = i = found = 0;
    while ((c = *(buffer + start + i)) != '\0' && !found) {
        if (c == *(string + i)) {
            if (*(string + ++i) == '\0')
                found = -1;
        }
        else {
            start++;
            i = 0;
        }
    }
    if (found)
        return (buffer + start);
    else
        return (NULL);
}