some settings for .dat file processing

wfs_read/readdat.c

@@ -0,0 +1,146 @@
+/*
+ * readdat.c
+ *
+ * Copyright 2016 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+#include <ctype.h>    // isspace
+#include <strings.h>  // strncasecmp
+#include "usefull_macros.h"
+#include "readdat.h"
+
+/**
+ * Get next text line ending with '\n' or '\n\r'
+ * @param start (i) - text in current line
+ * @param end   (i) - end of text
+ * @return            pointer to next line first character (spaces are omit) or NULL
+ */
+char *nextline(char *start, char* end){
+    if(!start || !end) return NULL;
+    while(start < end) // get next newline symbol
+        if(*start++ == '\n') break;
+    while(start < end){ // now skip all spaces, '\r' etc
+        if(isspace(*start)) ++start;
+        else break;
+    }
+    if(start == end) return NULL;
+    return start;
+}
+
+/**
+ * Read next double value from .dat file
+ * @param begin   (i) - beginning of data portion
+ * @param end     (i) - data end
+ * @param num     (o) - number read
+ * @return              pointer to next data item if line isn't end after current
+ *                          or pointer to next '\n' symbol (or `end`) if this value was last in string;
+ *                      NULL if there was an error during strtod
+ */
+char *read_double(char *begin, char *end, double *num){
+    char *nextchar;
+    if(!num || !begin|| !end || begin >= end) return NULL;
+    *num = strtod(begin, &nextchar);
+    if(!nextchar) // end of data
+        return end;
+    if(begin == nextchar || !isspace(*nextchar)){
+        char buf[10];
+        snprintf(buf, 10, "%s", begin);
+        WARNX(_("Not a number %s..."), buf);
+        return NULL;
+    }
+    while(nextchar < end){
+        char c = *nextchar;
+        if(isspace(c) && c != '\n') ++nextchar;
+        else break;
+    }
+    return nextchar;
+}
+
+/**
+ * Find in .dat file neader column number named `val`
+ * @param val   (i) - name of column to search
+ * @param dat   (i) - header start
+ * @param end   (i) - data end
+ * @return            number of column found or -1
+ */
+int get_hdrval(char *val, char *dat, char *end){
+    size_t l = strlen(val);
+    int i = 0;
+    while(dat < end){
+        char c = 0;
+        while(dat < end){ // skip spaces
+            c = *dat;
+            if(isspace(c) && c != '\n') ++dat;
+            else break;
+        }
+        if(c == '\n' || dat == end) return -1; // end of line or end of data reached
+        if(!strncasecmp(dat, val, l)) return i;
+        while(dat < end){ // skip non-spaces
+            if(!isspace(*dat)) ++dat;
+            else break;
+        }
+        ++i;
+    }
+    return -1;
+}
+
+/**
+ * Read .dat file and get Zernike coefficients from it
+ * @param fname (i) - .dat file name
+ * @param sz    (o) - size of coefficients' array
+ * @return            dynamically allocated array or NULL in case of error
+ */
+double *read_dat_file(char *fname, int *sz){
+    if(!fname) return NULL;
+    mmapbuf *dbuf = My_mmap(fname);
+    if(!dbuf) return NULL;
+    char *dat = dbuf->data, *eptr = dat + dbuf->len;
+    if(strncasecmp(dat, "time", 4)){
+        WARNX(_("Bad header"));
+        return NULL;
+    }
+    int rd = 0, skipfst = get_hdrval("piston", dat, eptr), L = Z_REALLOC_STEP;
+    if(skipfst < 0){
+        WARNX(_("Dat file don't have OSA Zernike coefficients"));
+        return NULL;
+    }
+    dat = nextline(dat, eptr);
+    double *zern = MALLOC(double, Z_REALLOC_STEP);
+    while(dat < eptr){
+        double d;
+        char *next = read_double(dat, eptr, &d);
+        if(!next) break;
+        dat = next;
+        if(skipfst > 0){ // skip this value
+            --skipfst;
+            continue;
+        }
+        if(++rd > L){
+            L += Z_REALLOC_STEP;
+            double *z_realloc = realloc(zern, L * sizeof(double));
+            if(!z_realloc){
+                WARN(_("Reallocation of memory failed"));
+                break;
+            }
+            zern = z_realloc;
+        }
+        zern[rd - 1] = d;
+        if(*next == '\n') break;
+    }
+    if(sz) *sz = rd;
+    return zern;
+}