/* vi: set sw=4 ts=4: * * truncate.c - set file length, extending sparsely if necessary * * Copyright 2011 Rob Landley <rob@landley.net> * * Not in SUSv4 USE_TRUNCATE(NEWTOY(truncate, "<1s#|c", TOYFLAG_BIN)) config TRUNCATE bool "truncate" default y help usage: truncate [-c] -s file... Set length of file(s), extending sparsely if necessary. -c Don't create file if it doesn't exist. -s New size */ #include "toys.h" DEFINE_GLOBALS( long size; ) #define TT this.truncate static void do_truncate(int fd, char *name) { if (fd<0) return; if (ftruncate(fd, TT.size)) { perror_msg("failed to set '%s' to '%ld'", name, TT.size); toys.exitval = EXIT_FAILURE; } } void truncate_main(void) { int cr = !(toys.optflags&1); // Create files with mask rwrwrw. // Nonexistent files are only an error if we're supposed to create them. loopfiles_rw(toys.optargs, O_WRONLY|(cr ? O_CREAT : 0), 0666, cr, do_truncate); }