diff options
Diffstat (limited to 'toys/posix')
| -rw-r--r-- | toys/posix/xargs.c | 62 |
1 files changed, 36 insertions, 26 deletions
diff --git a/toys/posix/xargs.c b/toys/posix/xargs.c index 79e7dea5..26c1b250 100644 --- a/toys/posix/xargs.c +++ b/toys/posix/xargs.c @@ -8,15 +8,14 @@ * TODO: -I Insert mode * TODO: -L Max number of lines of input per command * TODO: -x Exit if can't fit everything in one command - * TODO: -P NUM Run up to NUM processes at once -USE_XARGS(NEWTOY(xargs, "^E:P#optrn#<1(max-args)s#0[!0E]", TOYFLAG_USR|TOYFLAG_BIN)) +USE_XARGS(NEWTOY(xargs, "^E:P#<0=1optrn#<1(max-args)s#0[!0E]", TOYFLAG_USR|TOYFLAG_BIN)) config XARGS bool "xargs" default y help - usage: xargs [-0prt] [-s NUM] [-n NUM] [-E STR] COMMAND... + usage: xargs [-0prt] [-snE STR] COMMAND... Run command line one or more times, appending arguments from stdin. @@ -27,7 +26,8 @@ config XARGS -n Max number of arguments per command -o Open tty for COMMAND's stdin (default /dev/null) -p Prompt for y/n from tty before running each command - -r Don't run command with empty input (otherwise always run command once) + -P Parallel processes (default 1) + -r Don't run with empty input (otherwise always run command once) -s Size in bytes per command line -t Trace, print command line to stderr */ @@ -39,7 +39,7 @@ GLOBALS( long s, n, P; char *E; - long entries, bytes; + long entries, bytes, np; char delim; FILE *tty; ) @@ -91,13 +91,23 @@ static char *handle_entries(char *data, char **entry) return 0; } +// Handle SIGUSR1 and SIGUSR2 for -P +static void signal_P(int sig) +{ + if (sig == SIGUSR2 && TT.P>1) TT.P--; + else TT.P++; +} + void xargs_main(void) { struct double_list *dlist = 0, *dtemp; int entries, bytes, done = 0, status; - char *data = 0, **out; + char *data = 0, **out = 0; pid_t pid = 0; + xsignal_flags(SIGUSR1, signal_P, SA_RESTART); + xsignal_flags(SIGUSR2, signal_P, SA_RESTART); + // POSIX requires that we never hit the ARG_MAX limit, even if we try to // with -s. POSIX also says we have to reserve 2048 bytes "to guarantee // that the invoked utility has room to modify its environment variables @@ -138,7 +148,6 @@ void xargs_main(void) } } dlist_add(&dlist, data); - // Count data used if (!(data = handle_entries(data, 0))) continue; if (data == (char *)2) done++; @@ -150,8 +159,7 @@ void xargs_main(void) if (!TT.entries) { if (data) error_exit("argument too long"); - else if (pid) return; - else if (FLAG(r)) continue; + if (pid || FLAG(r)) goto reap_children; } // Fill out command line to exec @@ -170,7 +178,7 @@ void xargs_main(void) if (FLAG(p)) { fprintf(stderr, "?"); if (!TT.tty) TT.tty = xfopen("/dev/tty", "re"); - if (!fyesno(TT.tty, 0)) goto skip; + if (!fyesno(TT.tty, 0)) goto reap_children; } else fprintf(stderr, "\n"); } @@ -179,28 +187,30 @@ void xargs_main(void) xopen_stdio(FLAG(o) ? "/dev/tty" : "/dev/null", O_RDONLY); xexec(out); } - waitpid(pid, &status, 0); - - // xargs is yet another weird collection of exit value special cases, - // different from all the others. - if (WIFEXITED(status)) { - if (WEXITSTATUS(status) == 126 || WEXITSTATUS(status) == 127) { - toys.exitval = WEXITSTATUS(status); - return; - } else if (WEXITSTATUS(status) >= 1 && WEXITSTATUS(status) <= 125) { - toys.exitval = 123; - } else if (WEXITSTATUS(status) == 255) { - error_msg("%s: exited with status 255; aborting", out[0]); + TT.np++; + +reap_children: + while (TT.np) { + int xv = (TT.np == TT.P) || (!data && done); + + if (1>(xv = waitpid(-1, &status, WNOHANG*!xv))) break; + TT.np--; + xv = WIFEXITED(status) ? WEXITSTATUS(status) : WTERMSIG(status)+128; + if (xv == 255) { + error_msg("%s: exited with status 255; aborting", *out); toys.exitval = 124; - return; - } - } else toys.exitval = 127; + break; + } else if ((xv|1)==127) toys.exitval = xv; + else if (xv>127) xv = 125; + else if (xv) toys.exitval = 123; + } // Abritrary number of execs, can't just leak memory each time... -skip: llist_traverse(dlist, llist_free_double); dlist = 0; free(out); + out = 0; } + while (TT.np && -1 != wait(&status)) TT.np--; if (TT.tty) fclose(TT.tty); } |