ref: c59eb6d117c6dc99bc6e4330d3a9a3453888dee7
dir: /sys/src/cmd/swap.c/
#include <u.h> #include <libc.h> void main(int argc, char **argv) { int swapfd, cswfd; char buf[1024], *p; Dir *d; ARGBEGIN { } ARGEND; if(argc != 1){ fprint(2, "usage: swap file\n"); exits("usage"); } swapfd = -1; if(d = dirstat(p = *argv)){ if(d->mode & DMDIR){ p = getenv("sysname"); if(p == 0) p = "swap"; snprint(buf, sizeof buf, "%s/%sXXXXXXX", *argv, p); p = mktemp(buf); } else swapfd = open(p, ORDWR); } if(d == nil || (d->mode & DMDIR)){ if((swapfd = create(p, ORDWR|ORCLOSE, 0600)) >= 0){ Dir nd; nulldir(&nd); nd.mode = DMTMP|0600; dirfwstat(swapfd, &nd); } } if(swapfd < 0) sysfatal("%r"); if(fd2path(swapfd, p = buf, sizeof buf)) sysfatal("fd2path: %r"); if(putenv("swap", p) < 0) sysfatal("putenv: %r"); print("swap: %s\n", p); if((cswfd = open("/dev/swap", OWRITE)) < 0) sysfatal("open: %r"); if(fprint(cswfd, "%d", swapfd) < 0) sysfatal("write: %r"); exits(0); }