Add prefix support Hyejin Kim asked about.
diff --git a/toys/other/truncate.c b/toys/other/truncate.c
index d09818f..2b3d479 100644
--- a/toys/other/truncate.c
+++ b/toys/other/truncate.c
@@ -2,37 +2,61 @@
*
* Copyright 2011 Rob Landley <rob@landley.net>
-USE_TRUNCATE(NEWTOY(truncate, "<1s#|c", TOYFLAG_BIN))
+USE_TRUNCATE(NEWTOY(truncate, "<1s:|c", TOYFLAG_BIN))
config TRUNCATE
bool "truncate"
default y
help
- usage: truncate [-c] -s file...
+ usage: truncate [-c] -s SIZE file...
Set length of file(s), extending sparsely if necessary.
-c Don't create file if it doesn't exist.
- -s New size
+ -s New size (with optional prefix and suffix)
+
+ SIZE prefix: + add, - subtract, < shrink to, > expand to,
+ / block size rounding down, % block size rounding up
+ SIZE suffix: k=1024, m=1024^2, g=1024^3, t=1024^4, p=1024^5, e=1024^6
*/
#define FOR_truncate
#include "toys.h"
GLOBALS(
+ char *s;
+
long size;
+ int type;
)
static void do_truncate(int fd, char *name)
{
+ long long size;
+
if (fd<0) return;
- if (ftruncate(fd, TT.size)) perror_msg("'%s' to '%ld'", name, TT.size);
+
+ if (TT.type == -1) size = TT.size;
+ else {
+ size = fdlength(fd);
+ if (TT.type<2) size += TT.size*(1-(2*TT.type));
+ else if (TT.type<4) {
+ if ((TT.type==3) ? size > TT.size : size < TT.size) size = TT.size;
+ } else {
+ size = (size+(TT.type-4)*(TT.size-1))/TT.size;
+ size *= TT.size;
+ }
+ }
+ if (ftruncate(fd, size)) perror_msg("'%s' to '%lld'", name, size);
}
void truncate_main(void)
{
int cr = !(toys.optflags&1);
+ if (-1 != (TT.type = stridx("+-<>/%", *TT.s))) TT.s++;
+ TT.size = atolx(TT.s);
+
// Create files with mask rwrwrw.
// Nonexistent files are only an error if we're supposed to create them.
loopfiles_rw(toys.optargs, O_WRONLY|O_CLOEXEC|(cr ? O_CREAT : 0), 0666, cr,