The Linux Programming Interface: a linux and unix system Programming Handbook
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MONITORING CHILD PROCESSES 541 26.1 Waiting on a Child Process ........................................................................................ 541 26.1.1 The wait() System Call........................................................................... 541 26.1.2 The waitpid() System Call ...................................................................... 544 26.1.3 The Wait Status Value ........................................................................... 545 26.1.4 Process Termination from a Signal Handler .............................................. 549 26.1.5 The waitid() System Call ........................................................................ 550 26.1.6 The wait3() and wait4() System Calls...................................................... 552 26.2 Orphans and Zombies ............................................................................................... 553 26.3 The SIGCHLD Signal .................................................................................................... 555 26.3.1 Establishing a Handler for SIGCHLD .......................................................... 555 26.3.2 Delivery of SIGCHLD for Stopped Children ................................................. 559 26.3.3 Ignoring Dead Child Processes ............................................................... 559 26.4 Summary.................................................................................................................. 561 26.5 Exercises .................................................................................................................. 562 27 PROGRAM EXECUTION 563 27.1 Executing a New Program: execve() ............................................................................. 563 27.2 The exec() Library Functions......................................................................................... 567 27.2.1 The PATH Environment Variable ............................................................... 568 27.2.2 Specifying Program Arguments as a List................................................... 570 27.2.3 Passing the Caller’s Environment to the New Program ............................... 570 27.2.4 Executing a File Referred to by a Descriptor: fexecve() ................................ 571 27.3 Interpreter Scripts ...................................................................................................... 572 27.4 File Descriptors and exec() .......................................................................................... 575 27.5 Signals and exec() ..................................................................................................... 578 27.6 Executing a Shell Command: system() .......................................................................... 579 27.7 Implementing system() ................................................................................................ 582 27.8 Summary.................................................................................................................. 588 27.9 Exercises .................................................................................................................. 589 tải về 6.93 Mb. Chia sẻ với bạn bè của bạn:
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