First, the test command that sleeps random number of seconds ( sleeper.sh ): #!/bin/bash stime=$[$RANDOM % 20] sleep $sti... As comparison, synchronous pipe code: #include <sys/wait.h> #include <stdio.h> #in... Asynchronous pipe code: #include <sys/wait.h> #include <stdio.h> #in...

Example 1, from the pipe man page. The parent then writes the string contained in the program's command-line argument to the pipe, and the child reads this string a byte at a time from the pipe and echoes it on standard output. #include <sys/wait.h> #include <stdio.h> #in... Example 2, child execs command given at the command line, then writes to stdout (of child), which is piped to parent. Parent reads from pipe and writes to stdout (of parent). #include <sys/wait.h> #include <stdio.h> #in...

execl takes the full path name of the command and variable length of arguments terminated by NULL: execl("/bin/ls", "/bin/ls", "-r", "-t", "-l", NULL... where the second argument is argv[0] , but can be any string! execlp will try to find the command from $PATH , so full path to command is not needed: execl("ls", "ls", "-r", "-t", "-l", NULL); execv is the equivalent of execl , except that the arguments are passed in as a NULL terminated array: char *args[] = {"/bin/ls", "-r", "-t", "-l", NULL ... execvp is the equivalent of execvl , excep that the arguments are passed in as a NULL terminated array: char *args[] = {"ls", "-r", "-t", "-l", NULL }; ...

Exerpt from bash documentation. HISTORY EXPANSION The bash shell supports a history expansion feature that is similar to the history expansion in csh. This feature is enabled by default for interactive shells, and can be disabled using the +H option to the set builtin command. Non-interactive shells do not perform history expansion by default. History expansions introduce words from the history list into the input stream, making it easy to repeat commands, insert the arguments to a previous command into the current input line, or fix errors in previous commands quickly. History expansion is performed immediately after a complete line is read, before the shell breaks it into words. It takes place in two parts. The first is to determine which line from the history...

The MIPS CPU is able to run both big-endian and little-endian. So a system built on MIPS can be either big-endian (mips) or little-endian (mipsel). The file command shows the architecture: $ file ls ls: ELF 32-bit LSB executable, MIPS, ... but readelf will tell the endianness: $ readelf -h ls ELF Header: Magic: 7f 45...

rdoc documentation: usage(*args) Display usage information ... put something like this on top of your script: # == Synopsis # Blah blah blah. # ... method to display it def output_usage RDoc::usage('usa... bind it to the '-h' option via optionparser opts.on('-h', '--help') { output_help } ... source http://blog.toddwerth.com/entries/5

This is a list of built-in Android permission values: Permission Description Since API Level android.permission.ACCESS_CHECKIN_PROPERTIES Allows read/write access to the "properties" table in the checkin database, to change values that get uploaded. 1 android.permission.ACCESS_COARSE_LOCATION Allows an application to access coarse (e.g., Cell-ID, WiFi) location 1 android.permission.ACCESS_FINE_LOCATION Allows an application to access fine (e.g., GPS) location 1 android.permission.ACCESS_LOCATION_EXTRA_COMMANDS Allows an application to access extra location provider commands 1 android.permission.ACCESS_MOCK_LOCATION Allows an application to create mock location providers for testing 1 android.permission.ACCESS_NETWORK_STATE Allows applications to access information about networks 1 android.permission.ACCESS_SURFACE_FLINGER Allows an application to use SurfaceFlinger's low level features 1 android.permission.ACCESS_WIFI_STATE Allows applications to access information about Wi-Fi networks 1 android.permission.ACCOUNT_MANAGER Allows applications to call into AccountAuthenticators. Only the system can get this permission. 5 android.permission.AUTHENTICATE_ACCOUNTS...

In Android.mk , you can define LOCAL_JARJAR_RULES like this: LOCAL_JARJAR_RULES := $(LOCAL_PATH)/jarjar-rules.t... and in jarjar-rules.txt define a rule like this: rule org.bouncycastle.** com.android.@0 The build will change all org.bouncycastle to com.android.org.bouncycastle . Therefore, in your classes which are dependent on the library produced, the import statements should look like: import com.android.org.bouncycastle... Help for the jarjar utility (in prebuilt/common/jarjar/ ): $ java -jar jarjar-1.0rc8.jar Jar Jar Links - ...

String comparison operators: Operator Meaning -n str the length of str is nonzero. -z str the length of str is zero (0). str1 = str2 str1 and str2 are the same (note one equal sign, not two!). str1 != str2 str1 and str2 are not the same. str str is not a null string Examples: # empty string is not null if [ '' ]; then ... Numerical comparisons ( integer expressions only! ): Operator Meaning int1 -eq int2 int1 and int2 are numerically equal int1 -ne int2 int1 and int2 are numerically NOT equal int1 -gt int2 int1 is greater than int2 int1 -ge int2 int1 is greater than or equal to int2 int1 -lt int2 int1 is less than int2 int1 -le...

When you pass parameters from shell to Java, the list arguments may be messed up if there are spaces in the values. Start with a simple Java test class: public class EchoParams { public static voi... Tests: $ java EchoParams a b c Arg: a Arg: b Arg... Now wrap the command in a shell script ( echoparams.sh ): #!/bin/sh java EchoParams $* Tests: $ ./echoparams.sh a b c Arg: a Arg: b Arg... The quotes had no effect on the parameters list. Changing $* to $@ produces the same results. The correct way to quote the args list is: "$@" #!/bin/sh java EchoParams "$@" Test: $ ./echoparams.sh a b "c d" "1 2 3 4 5" Arg: a ...