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Shell scripting in OCaml.
This module contains basic blocks for shell scripting in OCaml. It tends to be safer than just using Unix.system because it handles errors more strictly.
type'a with_process_flags =
?use_extra_path:bool ->?timeout:Core.Time.Span.t option->?working_dir:string ->?setuid:int ->?setgid:int ->?env:
[ `Extend of (string * string) list| `Replace of (string * string) list ]->?verbose:bool ->?echo:bool ->?input:string ->?keep_open:bool ->?tail_len:int ->'a
This type is an umbrella type for all the command that dispatch a process. It comes with a list of arguments whose default value can be tweaked by set_defaults.
use_extra_path : if we fail to find the command in the path then we look for it extra_path
timeout : the command will raise Failed if the program doesn't do any IO for this period of time
working_dir : run the command in this directory
verbose : prints the output of the command
echo : print out the command before running it
input : a string to pipe through the program's standard in
export : a list of variable to export in the environement of the dispatched program
preserve_euid : pass the '-p' option to bash when running the command; this should disable the default bash behavior of replacing the effective user ID with the current value of the real user ID, useful in programs where privileges are escalated and de-escalated using seteuid(2)
WARNING: the input argument to this function should not be used because it can deadlock if the input is too big (~160kb?)
This is the list of flags for normal process dispatch. It is an extension of with_process_flags.
expect : an int list of valid return codes. default value is [0], if the return code of the dispatched is not in this list we will blowup with Process.Failure
Basic run functions
In all the functions below the command is specified with two arguments. The first one is a string representing the process to run. The second one is the list of arguments to pass.
Although the arguments do not need to be escaped there is still a risk that they might be interpreted as flags when they aren't. Most basic unix utilities provide the ability to pass arguments after "--" to avoid this.
Usage example:
let patch = run_full ~expect:[0;1] "diff" ["-u";"--";file1;file2]
Runs a command and returns its output line separated. Note: most commands print a newline at the end of their output so the shell prompt appears on its own line. If the output ends in a newline, it is stripped before splitting the output into a string list to avoid there being a final element in the list containing just the empty string.
In some cases, the newline should not be stripped (e.g., "cat" will not "add" a newline). If you care, use run_full for the entire buffer.
This function might terminate the program early the same way that piping through head -n 1 would. When that happens, exit code of the program gets ignored!
Fold over the lines in the stdout of a process; The `Continue/`Stop argument is there to allow early returning. eol specifies the end of line character used to separate the lines outputted by the the program
Dispatch to /bin/bash
All these function take a format (like printf) and run it through the shell.
Usage example:
sh "cp -- %s %s" (Filename.quote file1) (Filename.quote file2)
In general it is recommended to avoid using those too much and to prefer the run* family of function instead because it avoids pitfall like escaping issues and is much more straightforward to think about.
type('a, 'ret) sh_cmd = ('a, unit, string, 'ret)Core.format4->'a
This is the list of flags for dispatching processes in test mode. This is used to test the return code of the dispatched program. The return value of these functions will be :
true if the exit code is in true_v.
false if the exit code is in false_v and not in true_v.
variable used by dispatch command to find binaries not in the path. The default values contains only directory which should be in PATH and is only useful in environments where the PATH variable has been blown away.