From 2c59f669553677838022d65f2433b31a04bc632d Mon Sep 17 00:00:00 2001 From: Laurent Bercot Date: Tue, 5 May 2015 13:10:13 +0000 Subject: - add trap - rc for 2.1.2.0 --- INSTALL | 2 +- doc/index.html | 5 +- doc/trap.html | 98 +++++++++++++++++++++++++++ doc/upgrade.html | 7 ++ package/deps.mak | 3 + package/info | 2 +- package/modes | 1 + package/targets.mak | 1 + src/execline/deps-exe/trap | 2 + src/execline/trap.c | 161 +++++++++++++++++++++++++++++++++++++++++++++ 10 files changed, 278 insertions(+), 4 deletions(-) create mode 100644 doc/trap.html create mode 100644 src/execline/deps-exe/trap create mode 100644 src/execline/trap.c diff --git a/INSTALL b/INSTALL index 28d5af8..f912e75 100644 --- a/INSTALL +++ b/INSTALL @@ -6,7 +6,7 @@ Build Instructions - A POSIX-compliant C development environment - GNU make version 4.0 or later - - skalibs version 2.3.3.0 or later: http://skarnet.org/software/skalibs/ + - skalibs version 2.3.4.0 or later: http://skarnet.org/software/skalibs/ This software will run on any operating system that implements POSIX.1-2008, available at: diff --git a/doc/index.html b/doc/index.html index dda1445..5fb4b3c 100644 --- a/doc/index.html +++ b/doc/index.html @@ -51,7 +51,7 @@ shell's syntax, and has no security issues.

GNU make, version 4.0 or later. Please be aware that execline will not build with an earlier version.

skalibs version -2.3.3.0 or later. It's a build-time requirement. It's also a run-time +2.3.4.0 or later. It's a build-time requirement. It's also a run-time requirement if you link against the shared version of the skalibs library.

@@ -66,7 +66,7 @@ library.

Download

The current released version of execline is 2.1.1.1.
The current released version of execline is 2.1.2.0.
Alternatively, you can checkout a copy of the execline git repository:
```
 git clone git://git.skarnet.org/execline 
```

@@ -136,6 +136,7 @@ to your installation: the shebang lines for your system might be something like

The exec program

The tryexec program

The exit program

The trap program

(Basic block management) diff --git a/doc/trap.html b/doc/trap.html new file mode 100644 index 0000000..ff03c2e --- /dev/null +++ b/doc/trap.html @@ -0,0 +1,98 @@ + + + + + execline: the trap command + + + + + + +

+execline
+Software
+skarnet.org +

+ +

The `trap` program

+ +trap traps signals and runs a variety of commands according +to the signals it catches. + +

Interface

+ +

+ In an execlineb script: +

+ +

+     trap [ -x ] [ -t millisecs ]
+     {
+       [ timeout { progtimeout... } ]
+       [ SIGTERM { progsigterm... } ]
+       [ quit { progsigquit... } ]
+       [ 1 { progsighup... } ]
+       ...
+     }
+     prog...
+

+ +

trap reads a sequence of directives in a +block. It expects at least one +directive.
Each directive is a keyword followed by a block.
The keyword can be the special word timeout, a signal +name (case-insensitive, with or without the SIG prefix), + or a signal number. The block following it is a command line to +run when the specified event occurs.
trap sets traps for the various directives it reads. +A trap for SIGTERM will be triggered when the trap +program receives a SIGTERM. +A trap for timeout will be triggered when millisecs +milliseconds elapse without a signal being caught.
It spawns a child executing prog....
It sets the ! environment +variable to the pid of the prog... process.
Whenever it catches a signal, it spawns the program described in the +corresponding directive. It will not spawn a program for the same signal +twice: if the first subprocess is still active when another instance of the +same signal arrives, this second instance is ignored.
When prog... exits, trap exits with an +approximation of the same exit code.

+ +

Options

+ +

-x : forward signals. If this option is given, +any signal that trap receives and that is not explicitly +trapped will be sent to prog. By default, trap does +not forward any signals, and does not ignore them either - for instance a +SIGTERM, unless caught by a SIGTERM directive, will kill the +trap process (and leave prog running). With the +-x option, without a SIGTERM directive, a SIGTERM +will be still be caught by trap, that will send it to +prog.
-t millisecs : if a timeout +directive exists, the corresponding progtimeout... will be run +every time millisecs milliseconds elapse without trap +receiving a signal. By default, millisecs is 0, which means +infinite (i.e. a timeout directive will never trigger).

+ +

Notes

+ +

Programs defined in command line directives can start with +import ! to retrieve the pid of +prog in ${!}
trap is a standard shell builtin, with similar +functionality. It is more idiomatic, and probably more efficient, +to use that builtin in shell scripts, and to only use the +trap program in execline scripts.

+ + + diff --git a/doc/upgrade.html b/doc/upgrade.html index 121b210..ff1d40d 100644 --- a/doc/upgrade.html +++ b/doc/upgrade.html @@ -17,6 +17,13 @@

What has changed in execline

in 2.1.2.0

+ +

skalibs dependency bumped to 2.3.4.0
new command: trap

in 2.1.1.1

+#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define USAGE "trap [ -x ] [ -t timeout ] { signal { cmdline } ... } prog..." +#define dieusage() strerr_dieusage(100, USAGE) ; + +static pid_t pids[NSIG + 2] ; +static char const *const *argvs[NSIG + 1] ; + +static void action (unsigned int i, char const *const *envp) +{ + if (argvs[i]) + { + if (!pids[i]) + { + pids[i] = child_spawn0(argvs[i][0], argvs[i], envp) ; + if (!pids[i]) strerr_diefu2sys(111, "spawn ", argvs[i][0]) ; + } + } + else kill(pids[NSIG+1], i) ; +} + +int main (int argc, char const **argv, char const *const *envp) +{ + tain_t tto ; + int xfersigs = 0 ; + int argc1, spfd ; + unsigned int i = NSIG + 2 ; + PROG = "trap" ; + { + unsigned int t = 0 ; + subgetopt_t l = SUBGETOPT_ZERO ; + for (;;) + { + register int opt = subgetopt_r(argc, argv, "xt:", &l) ; + if (opt == -1) break ; + switch (opt) + { + case 'x' : xfersigs = 1 ; break ; + case 't' : if (!uint0_scan(l.arg, &t)) dieusage() ; break ; + default : dieusage() ; + } + } + argc -= l.ind ; argv += l.ind ; + if (t) tain_from_millisecs(&tto, t) ; + else tto = tain_infinite_relative ; + } + + if (!argc) dieusage() ; + argc1 = el_semicolon(argv) ; + if (!argc1) strerr_dief1x(100, "empty block") ; + if (argc1 >= argc) strerr_dief1x(100, "unterminated block") ; + if (argc1 + 1 == argc) dieusage() ; + argv[argc1] = 0 ; + while (i--) argvs[i] = 0 ; + i = 0 ; + tain_now_g() ; + spfd = selfpipe_init() ; + if (spfd < 0) strerr_diefu1sys(111, "selfpipe_init") ; + + while (i < (unsigned int)argc1) + { + int argc2 ; + unsigned int sig = (unsigned int)sig_number(argv[i] + (case_diffb(argv[i], 3, "sig") ? 0 : 3)) ; + if (!sig && !uint0_scan(argv[i], &sig) && case_diffs(argv[i], "timeout")) + strerr_dief3x(100, "unrecognized", " directive: ", argv[i]) ; + argc2 = el_semicolon(argv + ++i) ; + if (!argc2) + strerr_dief3x(100, "empty", " internal block for directive ", argv[i-1]) ; + if (i + argc2 >= argc1) + strerr_dief3x(100, "unterminated", " internal block for directive ", argv[i-1]) ; + if (argvs[sig]) + strerr_dief3x(100, "duplicate", " directive: ", argv[i-1]) ; + if (sig && selfpipe_trap(sig) < 0) + strerr_diefu2sys(111, "trap ", argv[i-1]) ; + argv[i + argc2] = 0 ; + argvs[sig] = argv + i ; + i += argc2 + 1 ; + } + if (!argvs[SIGCHLD] && selfpipe_trap(SIGCHLD) < 0) + strerr_diefu2sys(111, "trap ", "SIGCHLD") ; + + if (xfersigs) + { + sigset_t full ; + sigfillset(&full) ; + sigdelset(&full, SIGCHLD) ; + for (i = 1 ; i <= NSIG ; i++) + if (!argvs[i] && sigismember(&full, i) > 0 && selfpipe_trap(i) < 0) + { + char fmt[UINT_FMT] ; + fmt[uint_fmt(fmt, i)] = 0 ; + strerr_diefu4sys(111, "auto-", "trap ", "signal ", fmt) ; + } + } + + pids[NSIG+1] = child_spawn0(argv[argc1 + 1], argv + argc1 + 1, envp) ; + if (!pids[NSIG+1]) strerr_diefu2sys(111, "spawn ", argv[argc1 + 1]) ; + + { + iopause_fd x = { .fd = spfd, .events = IOPAUSE_READ } ; + char modif[2 + UINT64_FMT] = "!=" ; + unsigned int envlen = env_len(envp) ; + char const *newenvp[envlen + 2] ; + i = 2 + uint64_fmt(modif + 2, pids[NSIG+1]) ; + modif[i++] = 0 ; + if (!env_merge(newenvp, envlen + 2, envp, envlen, modif, i)) + strerr_diefu1sys(111, "adjust environment") ; + for (;;) + { + tain_t deadline ; + register int r ; + tain_add_g(&deadline, &tto) ; + r = iopause_g(&x, 1, &deadline) ; + if (r < 0) strerr_diefu1sys(111, "iopause") ; + if (!r) action(0, newenvp) ; + else + { + int cont = 1 ; + while (cont) + { + r = selfpipe_read() ; + switch (r) + { + case -1 : strerr_diefu1sys(111, "selfpipe_read") ; + case 0 : cont = 0 ; break ; + case SIGCHLD : + for (;;) + { + int id, wstat ; + id = wait_pids_nohang(pids, NSIG + 2, &wstat) ; + if (id < 0 && errno != ECHILD) + strerr_diefu1sys(111, "wait") ; + if (id <= 0) break ; + pids[id - 1] = 0 ; + if (id == NSIG + 2) return wait_estatus(wstat) ; + } + if (!argvs[SIGCHLD]) break ; + default : + action(r, newenvp) ; + } + } + } + } + } +} -- cgit v1.2.3