{"id":702,"date":"2014-05-24T00:01:16","date_gmt":"2014-05-24T07:01:16","guid":{"rendered":"http:\/\/c-for-dummies.com\/blog\/?p=702"},"modified":"2014-05-31T07:45:21","modified_gmt":"2014-05-31T14:45:21","slug":"word-wrap-filter-walkthrough","status":"publish","type":"post","link":"https:\/\/c-for-dummies.com\/blog\/?p=702","title":{"rendered":"Word Wrap Filter Walkthrough"},"content":{"rendered":"

In last week’s Lesson<\/a>, I presented code that shows one way to wrap incoming streaming text. It’s not the easiest thing. Let me explain how last week’s code attempts to solve the problem.
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\nHere’s a copy of the word wrap filter code from last week’s Lesson:<\/p>\n

\r\n#include <stdio.h>\r\n#include <stdlib.h>\r\n#include <ctype.h>\r\n\r\nint main()\r\n{\r\n    char *buffer,*space;\r\n    int c,x,right_margin,position;\r\n\r\n    right_margin = 40;      \/* make the margin variable *\/<\/span>\r\n\r\n    \/* allocate space for the buffer *\/<\/span>\r\n    buffer = malloc(sizeof(char) * right_margin);\r\n    if(buffer==NULL)\r\n    {\r\n        perror(\"Unable to allocate buffer\");\r\n        exit(1);\r\n    }\r\n\r\n    *buffer = '\\0';         \/* initialize buffer *\/<\/span>\r\n    space = buffer;         \/* Initialize space *\/<\/span>\r\n    position = 0;           \/*  and position *\/<\/span>\r\n    c = 65;                 \/* Ensure that it loops *\/<\/span>\r\n    while(c)\r\n    {\r\n        c = getchar();          \/* fetch character *\/<\/span>\r\n        *(buffer+position) = c; \/* store character *\/<\/span>\r\n        \/* if c is white space, save its location *\/<\/span>\r\n        if(isspace(c))\r\n            space = buffer+position;\r\n        position++;             \/* buffer index *\/<\/span>\r\n        \/* check to see if the margin has been reached *\/<\/span>\r\n        if(position > right_margin)\r\n        {\r\n            \/* Display the buffer up to the space *\/<\/span>\r\n            for(x=0;x<right_margin;x++)\r\n            {\r\n                if( *(buffer+x)==EOF)   \/* exit on EOF *\/<\/span>\r\n                    exit(0);\r\n                if(buffer+x == space)   \/* stop at w\/s char *\/<\/span>\r\n                    break;\r\n                putchar(*(buffer+x));\r\n            }\r\n            putchar('\\n');\r\n            \/* copy the rest of the buffer to the start *\/<\/span>\r\n            position = 0;\r\n            space++;\r\n            while(space <= buffer+right_margin)\r\n            {\r\n                *(buffer+position) = *(space);\r\n                position++;\r\n                space++;\r\n            }\r\n            \/* Re-initialize the space pointer *\/<\/span>\r\n            space = buffer;\r\n        }\r\n    }\r\n\r\n    return(0);\r\n}<\/pre>\n
To assist you in understanding how the code works, I’ve concocted the following video presentation. Review the video and then read my commentary to see how the code works.<\/p>\n
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