ref: 75d44bc306ffcbaadaa18c161bf54071304510b0
dir: /sys/src/cmd/pipefile.c/
#include <u.h> #include <libc.h> #define TEMP "/n/temp" void usage(void) { fprint(2, "usage: pipefile [-d] [-r command] [-w command] file\n"); exits("usage"); } void connect(char *cmd, int fd0, int fd1) { switch(rfork(RFPROC|RFFDG|RFREND|RFNOWAIT)){ case -1: sysfatal("fork %s: %r", cmd); break; default: close(fd0); close(fd1); return; case 0: dup(fd0, 0); dup(fd1, 1); close(fd0); close(fd1); execl("/bin/rc", "rc", "-c", cmd, nil); sysfatal("exec %s: %r", cmd); break; } } void main(int argc, char *argv[]) { char *file; char *rcmd, *wcmd; int fd0, fd1, ifd0, ifd1, dupflag; rfork(RFNOTEG); dupflag = 0; rcmd = wcmd = nil; ARGBEGIN{ case 'd': dupflag = 1; break; case 'r': rcmd = EARGF(usage()); break; case 'w': wcmd = EARGF(usage()); break; default: usage(); }ARGEND if(argc!=1 || (rcmd==nil && wcmd==nil)) usage(); if(rcmd == nil) rcmd = "/bin/cat"; if(wcmd == nil) wcmd = "/bin/cat"; file = argv[0]; if(dupflag){ ifd0 = open(file, ORDWR); if(ifd0 < 0) sysfatal("open %s: %r", file); ifd1 = dup(ifd0, -1); }else{ ifd0 = open(file, OREAD); if(ifd0 < 0) sysfatal("open %s: %r", file); ifd1 = open(file, OWRITE); if(ifd1 < 0) sysfatal("open %s: %r", file); } if(bind("#|", TEMP, MREPL) < 0) sysfatal("bind pipe %s: %r", TEMP); if(bind(TEMP "/data", file, MREPL) < 0) sysfatal("bind %s %s: %r", TEMP "/data", file); fd0 = open(TEMP "/data1", OREAD); if(fd0 < 0) sysfatal("open %s: %r", TEMP "/data1"); connect(wcmd, fd0, ifd1); fd1 = open(TEMP "/data1", OWRITE); if(fd1 < 0) sysfatal("open %s: %r", TEMP "/data1"); connect(rcmd, ifd0, fd1); unmount(nil, TEMP); exits(nil); }