aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorRob Landley <rob@landley.net>2020-06-10 17:52:23 -0500
committerRob Landley <rob@landley.net>2020-06-10 17:52:23 -0500
commit2d5b8f9c1bcd09932f3322823a26ee4c0a543b46 (patch)
tree875301ad276e27eb6857dd3013ab2f4c11c555a7
parenta01cee764f620c154fcccb688d7b1a742f7f687e (diff)
downloadtoybox-2d5b8f9c1bcd09932f3322823a26ee4c0a543b46.tar.gz
Chunk of job control pumbing.
-rw-r--r--toys/pending/sh.c325
1 files changed, 154 insertions, 171 deletions
diff --git a/toys/pending/sh.c b/toys/pending/sh.c
index e77ebe6f..4e626c75 100644
--- a/toys/pending/sh.c
+++ b/toys/pending/sh.c
@@ -46,6 +46,11 @@
* reserved words
* ! case coproc do done elif else esac fi for function if in select
* then until while { } time [[ ]]
+ *
+ * Flow control statements:
+ *
+ * if/then/elif/else/fi, for select while until/do/done, case/esac,
+ * {/}, [[/]], (/), function assignment
USE_SH(NEWTOY(cd, ">1LP[-LP]", TOYFLAG_NOFORK))
USE_SH(NEWTOY(eval, 0, TOYFLAG_NOFORK))
@@ -143,6 +148,21 @@ config EXPORT
With no arguments list exported variables/attributes as "declare" statements.
+config JOBS
+ bool
+ default n
+ depends on SH
+ help
+ usage: jobs [-lnprs] [%JOB | -x COMMAND...]
+
+ List running/stopped background jobs.
+
+ -l Include process ID in list
+ -n Show only new/changed processes
+ -p Show process IDs only
+ -r Show running processes
+ -s Show stopped processes
+
config SHIFT
bool
default n
@@ -167,66 +187,50 @@ GLOBALS(
} exec;
};
- // keep lineno here, we use it to work around a compiler bug
+ // keep lineno here, we use it to work around a compiler limitation
long lineno;
char *ifs, *isexec;
- struct double_list functions;
unsigned options, jobcnt;
- int hfd, pid, varslen, shift, cdcount;
- unsigned long long SECONDS;
+ int hfd, pid, bangpid, varslen, shift, cdcount;
+ long long SECONDS;
struct sh_vars {
long flags;
char *str;
} *vars;
- // Running jobs for job control.
- struct sh_job {
- struct sh_job *next, *prev;
- unsigned jobno;
-
- // Every pipeline has at least one set of arguments or it's Not A Thing
- struct sh_arg {
- char **v;
- int c;
- } pipeline;
-
- // null terminated array of running processes in pipeline
- struct sh_process {
- struct sh_process *next, *prev;
- struct arg_list *delete; // expanded strings
- // undo redirects, a=b at start, child PID, exit status, has !
- int *urd, envlen, pid, exit, not;
- struct sh_arg arg;
- } *procs, *proc;
- } *jobs, *job;
-
- struct sh_process *pp;
- struct sh_arg *arg;
+ // Parsed function
+ struct sh_function {
+ char *name;
+ struct sh_pipeline { // pipeline segments
+ struct sh_pipeline *next, *prev, *end;
+ int count, here, type; // TODO abuse type to replace count during parsing
+ struct sh_arg {
+ char **v;
+ int c;
+ } arg[1];
+ } *pipeline;
+ struct double_list *expect; // should be zero at end of parsing
+ } *functions;
+
+// TODO ctrl-Z suspend should stop script
+ struct sh_process {
+ struct sh_process *next, *prev; // | && ||
+ struct arg_list *delete; // expanded strings
+ // undo redirects, a=b at start, child PID, exit status, has !, job #
+ int *urd, envlen, pid, exit, not, job;
+ long long when; // when job backgrounded/suspended
+// TODO struct sh_arg *raw; // for display
+ struct sh_arg arg;
+ } *pp; // currently running process
+
+ struct sh_arg jobs, *arg; // job list, command line args for $* etc
)
// Can't yet avoid this prototype. Fundamental problem is $($($(blah))) nests,
// leading to function loop with run->parse->run
static int sh_run(char *new);
-// Pipeline segments
-struct sh_pipeline {
- struct sh_pipeline *next, *prev, *end;
- int count, here, type;
- struct sh_arg arg[1];
-};
-
-// scratch space (state held between calls). Don't want to make it global yet
-// because this could be reentrant.
-struct sh_function {
- char *name;
- struct sh_pipeline *pipeline;
- struct double_list *expect;
-// TODO: lifetime rules for arg? remember "shift" command.
- struct sh_arg *arg; // arguments to function call
- char *end;
-};
-
#define BUGBUG 0
// call with NULL to just dump FDs
@@ -843,6 +847,7 @@ if (BUGBUG) dprintf(255, "expand %s\n", str);
qq += 2;
while ((cc = str[ii++]) != '\'') new[oo++] = cc;
}
+
// both types of subshell work the same, so do $( here not in '$' below
// TODO $((echo hello) | cat) ala $(( becomes $( ( retroactively
} else if (cc == '`' || (cc == '$' && strchr("([", str[ii]))) {
@@ -939,7 +944,6 @@ dprintf(2, "TODO: do math for %.*s\n", kk, s);
// x can be @*
// TODO: $_ is last arg of last command, and exported as path to exe run
-// TODO: $! is PID of most recent background job
if (ifs);
else if (cc == '-') {
s = ifs = xmalloc(8);
@@ -951,6 +955,7 @@ dprintf(2, "TODO: do math for %.*s\n", kk, s);
} else if (cc == '?') ifs = xmprintf("%d", toys.exitval);
else if (cc == '$') ifs = xmprintf("%d", TT.pid);
else if (cc == '#') ifs = xmprintf("%d", TT.arg->c?TT.arg->c-1:0);
+ else if (cc == '!') ifs = xmprintf("%d"+2*!TT.bangpid, TT.bangpid);
else if (cc == '*' || cc == '@') aa = TT.arg->v+1;
else if (isdigit(cc)) {
for (kk = ll = 0; kk<jj && isdigit(ss[kk]); kk++)
@@ -1953,13 +1958,6 @@ flush:
return 0-!!s;
}
-/* Flow control statements:
-
- if/then/elif/else/fi, for select while until/do/done, case/esac,
- {/}, [[/]], (/), function assignment
-*/
-
-
// wait for every process in a pipeline to end
static int wait_pipeline(struct sh_process *pp)
{
@@ -2015,11 +2013,11 @@ static int pipe_segments(char *ctl, int *pipes, int **urd)
struct blockstack {
struct blockstack *next;
- struct sh_pipeline *start;
- struct sh_process *pin; // processes piping into this block
+ struct sh_pipeline *start, *middle;
+ struct sh_process *pp; // list of processes piping in to us
int run, loop, *urd, pout;
struct sh_arg farg; // for/select arg stack
- struct arg_list *fdelete; // farg's cleanup list
+ struct arg_list *fdelete; // farg's cleanup list
char *fvar; // for/select's iteration variable name
};
@@ -2049,32 +2047,41 @@ static void run_function(struct sh_pipeline *pl)
int *urd = 0, pipes[2] = {-1, -1};
long i;
+// TODO: "echo | read i" is backgroundable with ctrl-Z despite read = builtin.
+// probably have to inline run_command here to do that? Implicit ()
+// also "X=42 | true; echo $X" doesn't get X.
+// I.E. run_subshell() here sometimes? (But when?)
+// TODO: bash supports "break &" and "break > file". No idea why.
+// TODO If we just started a new pipeline, implicit parentheses (subshell)
// TODO can't free sh_process delete until ready to dispose else no debug output
+/*
+TODO: a | b | c needs subshell for builtins?
+ - anything that can produce output
+ - echo declare dirs
+ (a; b; c) like { } but subshell
+ when to auto-exec? ps vs sh -c 'ps' vs sh -c '(ps)'
+*/
+
TT.hfd = 10;
// iterate through pipeline segments
while (pl) {
- struct sh_arg *arg = pl->arg;
- char *s = *arg->v, *ss = arg->v[1], *ctl = arg->v[arg->c];
-if (BUGBUG) dprintf(255, "%d runtype=%d %s %s\n", getpid(), pl->type, s, ctl);
- // Is this an executable segment?
- if (!pl->type) {
+ char *ctl = pl->end->arg->v[pl->end->arg->c],
+ *s = *pl->arg->v, *ss = pl->arg->v[1];
- // Skip disabled block
+ // Skip disabled blocks, handle pipes
+ if (pl->type<2) {
if (blk && !blk->run) {
- pl = pl->next;
+ pl = pl->end->next;
continue;
}
if (pipe_segments(ctl, pipes, &urd)) break;
+ }
- // If we just started a new pipeline, implicit parentheses (subshell)
-
-// TODO: "echo | read i" is backgroundable with ctrl-Z despite read = builtin.
-// probably have to inline run_command here to do that? Implicit ()
-// also "X=42 | true; echo $X" doesn't get X.
-
- // TODO: bash supports "break &" and "break > file". No idea why.
+if (BUGBUG) dprintf(255, "%d runtype=%d %s %s\n", getpid(), pl->type, s, ctl);
+ // Is this an executable segment?
+ if (!pl->type) {
// Is it a flow control jump? These aren't handled as normal builtins
// because they move *pl to other pipeline segments which is local here.
@@ -2083,7 +2090,7 @@ if (BUGBUG) dprintf(255, "%d runtype=%d %s %s\n", getpid(), pl->type, s, ctl);
// How many layers to peel off?
i = ss ? atol(ss) : 0;
if (i<1) i = 1;
- if (!blk || arg->c>2 || ss[strspn(ss, "0123456789")]) {
+ if (!blk || pl->arg->c>2 || ss[strspn(ss, "0123456789")]) {
syntax_err(s);
break;
}
@@ -2092,30 +2099,19 @@ if (BUGBUG) dprintf(255, "%d runtype=%d %s %s\n", getpid(), pl->type, s, ctl);
if (!--i && *s == 'c') pl = blk->start;
else pl = pop_block(&blk, pipes);
if (i) {
- syntax_err("break outside loop");
+ syntax_err("break");
break;
}
- pl = pl->next;
- continue;
-
- // Parse and run next command
} else {
-
-// TODO: "echo | read i" is backgroundable with ctrl-Z despite read = builtin.
-// probably have to inline run_command here to do that? Implicit ()
-// also "X=42 | true; echo $X" doesn't get X.
-// I.E. run_subshell() here sometimes? (But when?)
-
- dlist_add_nomalloc((void *)&pplist, (void *)run_command(arg));
- }
-
- if (*pipes == -1) {
- toys.exitval = wait_pipeline(pplist);
- llist_traverse(pplist, free_process);
- pplist = 0;
- // for && and || skip pipeline segment(s) based on return code
- while (ctl && !strcmp(ctl, toys.exitval ? "&&" : "||"))
- ctl = (pl = pl->type ? pl->end : pl->next)?pl->arg->v[pl->arg->c]:0;
+ // Parse and run next command, saving resulting process
+ dlist_add_nomalloc((void *)&pplist, (void *)run_command(pl->arg));
+
+ // Three cases: backgrounded&, pipelined|, last process in pipeline;
+ if (ctl && !strcmp(ctl, "&")) {
+ pplist->job = ++TT.jobcnt;
+ arg_add(&TT.jobs, (void *)pplist);
+ pplist = 0;
+ }
}
// Start of flow control block?
@@ -2123,115 +2119,90 @@ if (BUGBUG) dprintf(255, "%d runtype=%d %s %s\n", getpid(), pl->type, s, ctl);
struct sh_process *pp = 0;
int rc;
- // are we entering this block (rather than looping back to it)?
- if (!blk || blk->start != pl) {
-
- // If it's a nested block we're not running, skip ahead.
- if (blk && !blk->run) {
- pl = pl->end->next;
- continue;
- }
+ // Save new block and add it to the stack.
+ new = xzalloc(sizeof(*blk));
+ new->next = blk;
+ blk = new;
+ blk->start = pl;
+ blk->run = 1;
+
+ // push pipe and redirect context into block
+ blk->pout = *pipes;
+ *pipes = -1;
+ pp = expand_redir(pl->end->arg, 1, blk->urd = urd);
+ urd = 0;
+ rc = pp->exit;
+ if (pp->arg.c) {
+ syntax_err(*pp->arg.v);
+ rc = 1;
+ }
- // If previous piped into this block, save context until block end
- if (pipe_segments(pl->end->arg->v[pl->end->arg->c], pipes, &urd)) break;
-
- // It's a new block we're running, save context and add it to the stack.
- new = xzalloc(sizeof(*blk));
- new->next = blk;
- blk = new;
- blk->start = pl;
- blk->run = 1;
-
- // save context until block end
- blk->pout = *pipes;
- blk->urd = urd;
- urd = 0;
- *pipes = -1;
-
- // Perform redirects listed at end of block
- pp = expand_redir(pl->end->arg, 1, blk->urd);
- blk->urd = pp->urd;
- rc = pp->exit;
- if (pp->arg.c) {
- syntax_err(*pp->arg.v);
- rc = 1;
- }
+ // Cleanup if we're not doing a subshell
+ if (rc || strcmp(s, "(")) {
llist_traverse(pp->delete, free);
free(pp);
if (rc) {
toys.exitval = rc;
break;
}
+ } else {
+ // Create new process
+ if (!CFG_TOYBOX_FORK) {
+ ss = pl2str(pl->next);
+ pp->pid = run_subshell(ss, strlen(ss));
+ free(ss);
+ } else if (!(pp->pid = fork())) {
+ run_function(pl->next);
+ _exit(toys.exitval);
+ }
+
+ // add process to current pipeline same as type 0
+ dlist_add_nomalloc((void *)&pplist, (void *)pp);
+ pl = pl->end;
+ continue;
}
+pp = 0;
// What flow control statement is this?
// {/} if/then/elif/else/fi, while until/do/done - no special handling
- // for select/do/done
+ // for select/do/done: populate blk->farg with expanded arguments (if any)
if (!strcmp(s, "for") || !strcmp(s, "select")) {
- if (blk->loop);
+ if (blk->loop); // TODO: still needed?
else if (!strncmp(blk->fvar = ss, "((", 2)) {
blk->loop = 1;
dprintf(2, "TODO skipped init for((;;)), need math parser\n");
- } else {
- // populate blk->farg with expanded arguments
- if (pl->next->type == 's') {
- for (i = 1; i<pl->next->arg->c; i++)
- if (expand_arg(&blk->farg, pl->next->arg->v[i], 0, &blk->fdelete))
- break;
- if (i != pl->next->arg->c) {
- pl = pop_block(&blk, pipes)->next;
- continue;
- }
- // this can't fail
- } else expand_arg(&blk->farg, "\"$@\"", 0, &blk->fdelete);
- }
+ // in LIST
+ } else if (pl->next->type == 's') {
+ for (i = 1; i<pl->next->arg->c; i++)
+ if (expand_arg(&blk->farg, pl->next->arg->v[i], 0, &blk->fdelete))
+ break;
+ if (i != pl->next->arg->c) pl = pop_block(&blk, pipes);
+ // in without LIST. (This expansion can't fail.)
+ } else expand_arg(&blk->farg, "\"$@\"", 0, &blk->fdelete);
// TODO case/esac [[/]] ((/)) function/}
-/*
-TODO: a | b | c needs subshell for builtins?
- - anything that can produce output
- - echo declare dirs
- (a; b; c) like { } but subshell
- when to auto-exec? ps vs sh -c 'ps' vs sh -c '(ps)'
-*/
-
- // subshell
- } else if (!strcmp(s, "(")) {
- if (!CFG_TOYBOX_FORK) {
- ss = pl2str(pl->next);
- pp->pid = run_subshell(ss, strlen(ss));
- free(ss);
- } else {
- if (!(pp->pid = fork())) {
- run_function(pl->next);
- _exit(toys.exitval);
- }
- }
-
- dlist_add_nomalloc((void *)&pplist, (void *)pp);
- pl = pl->end;
- continue;
}
// gearshift from block start to block body (end of flow control test)
} else if (pl->type == 2) {
- // Handle if statement
+ blk->middle = pl;
+
+ // Handle if/else/elif statement
if (!strcmp(s, "then")) blk->run = blk->run && !toys.exitval;
else if (!strcmp(s, "else") || !strcmp(s, "elif")) blk->run = !blk->run;
+
+ // Loop
else if (!strcmp(s, "do")) {
ss = *blk->start->arg->v;
if (!strcmp(ss, "while")) blk->run = blk->run && !toys.exitval;
else if (!strcmp(ss, "until")) blk->run = blk->run && toys.exitval;
- else if (blk->loop >= blk->farg.c) {
- blk->run = 0;
- pl = pl->end;
- continue;
- } else if (!strncmp(blk->fvar, "((", 2)) {
+ else if (blk->loop >= blk->farg.c) pl = pop_block(&blk, pipes);
+ else if (!strncmp(blk->fvar, "((", 2)) {
dprintf(2, "TODO skipped running for((;;)), need math parser\n");
} else setvarval(blk->fvar, blk->farg.v[blk->loop++]);
}
@@ -2239,18 +2210,30 @@ dprintf(2, "TODO skipped running for((;;)), need math parser\n");
// end of block, may have trailing redirections and/or pipe
} else if (pl->type == 3) {
- // if we end a block we're not in, we started in a block.
+ // if we end a block we're not in, we started in a block (subshell)
if (!blk) break;
// repeating block?
if (blk->run && !strcmp(s, "done")) {
- pl = blk->start;
+ pl = blk->middle;
continue;
}
pop_block(&blk, pipes);
} else if (pl->type == 'f') pl = add_function(s, pl);
+ // If we ran a process and didn't pipe output or background, wait for exit
+ if (pplist && *pipes == -1) {
+ toys.exitval = wait_pipeline(pplist);
+ llist_traverse(pplist, free_process);
+ pplist = 0;
+ }
+
+ // for && and || skip pipeline segment(s) based on return code
+ if (pl->type == 1 || pl->type == 3)
+ while (ctl && !strcmp(ctl, toys.exitval ? "&&" : "||"))
+ ctl = (pl = pl->type ? pl->end : pl->next)?pl->arg->v[pl->arg->c]:0;
+
pl = pl->next;
}