/* rev.c - reverse lines of a set of given input files * * Copyright 2012 Elie De Brauwer <eliedebrauwer@gmail.com> USE_REV(NEWTOY(rev, NULL, TOYFLAG_USR|TOYFLAG_BIN)) config REV bool "rev" default y help usage: rev [FILE...] Output each line reversed, when no files are given stdin is used. */ #include "toys.h" void do_rev(int fd, char *name) { char *c; for (;;) { int len, i; if (!(c = get_line(fd))) break; len = strlen(c) - 1; for (i = 0; i <= len/2; i++) { char tmp = c[i]; c[i] = c[len-i]; c[len-i] = tmp; } xputs(c); free(c); } } void rev_main(void) { loopfiles(toys.optargs, do_rev); }