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POHelp needed in Segmentation Error in my C code
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copied!<p>I have been trying to identify where my program generates segmentation all to no avail. I need help in pin-pointing which of the strings operations or char pointers is causing the segmentation fault during runtime. The program compiles successfully but gives segmentation error during run-time.</p> <pre><code>#include<curses.h> #include<strings.h> #include<unistd.h> #include<stdlib.h> /*Implements a Scrolling headband that takes a string argument and continously scrolls*/ int main(int argc, char* argv[]) { /*A Substring function to return substring of a string*/ char *substr(const char *src, int start, int len); /*Appends a character to the Given string*/ void append(char* s, char c); /***Check if the argument is invalid***/ if(argc!=2) { puts("Invalid number of arguments: Usage:headband <String>"); } /**Get headtext from the string argument argv[1]**/ char *headtext = argv[1]; /*headband(headtext);*/ /*temporary variable to store strings as execution progresses*/ char temp[100]; /*Counter for streaming and scolling headband text*/ int count = 0; /*Placeholder for temporary headband text*/ char hold[100]; int i; /*maximum x and y co-ordinates of the Screen*/ int max_x,max_y; /*Initialize screen for ncurses*/ initscr(); /*Don't show cursor*/ curs_set(0); /*Get terminal console dimensions*/ getmaxyx(stdscr, max_y, max_x); /*Get console width set to default console screen width=80*/ int consolewidth = max_x; /*Clear the screen*/ clear(); /*Set the first value as end of String for the momment*/ temp[0] = '\0'; /*Run this loop continuously to keep scrolling*/ for (;;) { for(i=0; i < strlen(headtext); i++) { count++; /*Append headband text character by character to string hold*/ append(temp, headtext[i]); move(0,consolewidth - count); if (consolewidth - count > 0) { mvaddstr(0,console_width-count,temp); refresh(); } else if (consolewidth - count == 0) { strcpy(hold, temp); char q; int com = i; for(;;) { /*Scroll text by triming one character at a time*/ /*from the left, then adding that character to the*/ /*right side of the text*/ com = com + 1; if (com < strlen(headtext)) { q = headtext[com]; } else { com = 0; q = headtext[com]; //q = hold[0]; } strcpy(hold, substr(hold, 1, strlen(hold) - 1)); append(hold, q); move(0,0); clear(); mvaddstr(0,0,hold); refresh(); usleep(50); } } usleep(50); } } return 0; } /*A Substring function to return substring of a string*/ char * substr(const char *src, int start, int len) { char *dest = malloc(len+1); if (dest) { memcpy(dest, src+start, len); dest[len] = '\0'; } return dest; } /*Appends a character to the Given string*/ void append(char s[], char c) { int len = strlen(s); s[len] = c; s[len+1] = '\0'; } </code></pre>

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