Open a pipe to a command and execute the command.
Description |
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popen() executes the command specified by command. It does
this as if it spawns a child process with fork(), then the
child process invokes the shell sh with
execl (shellpath, "sh", "-c", command, NULL);
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where shellpath is the path name of the file that contains
the shell.
popen() establishes a pipe between command and the process
which executes popen(). The result of popen() is a FILE *
pointer that can be used to read/write on this pipe. If
mode is "r", standard output from command is piped to the
process which calls popen(). Data shipped along this pipe
can be read with normal I/O calls using the FILE * pointer
returned by popen(). If mode is "w", output written to
the pipe by the process which calls popen() is sent as the
standard input to command.
Streams opened with popen() should be closed with
pclose().
