HP C/iX Reference Manual (31506-90011)

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124 Chapter8

Compiling and Running HP C/iX Programs

Running HP C/iX Programs

You can run HP C/iX programs using the RUN command or by entering the program name

(an implied run). You can pass parameters to the main program and redirect the standard

input (stdin), standard output (stdout), and error output (stderr) to speciﬁc ﬁles by

using the INFO string.

Program Parameters

You can pass parameters to an HP C/iX program by declaring them in the function main as

shown in the following example:

main(argc, argv, envp, parm, info)

int argc;

char *argv[];

char *envp[];

int parm;

char *info;

NOTE

The envp parameter is required as a placeholder in the formal parameter list

for main. This parameter is not initialized on MPE/iX and must not be used. It

is provided for compatibility with programs on other systems that pass envp

to main.

You invoke the program (called MYPROG) with the following command:

RUN MYPROG; INFO="STR1 STR2 STR3"; PARM=11

The C compiler separates the INFO string into argv arguments using blanks as argument

delimiters and sets argc to the number of argv elements. To pass an argument that

contains embedded blanks, enclose the argument in quotes. Use single quotes to delimit

the argument if the INFO string is enclosed in double quotes; use double quotes if the

INFO string is enclosed in single quotes. A quote may be included within a quoted string

by escaping the quote with another quote similar to the manner in which the MPE/iX

command interpreter allows quotes to be passed in the INFO string. The argv[0]

argument is set equal to the program name, and argv[argc] is set equal to NULL. The

PARM and INFO values are passed unchanged to the program. The order of the

declaration of parameters to main is signiﬁcant, but the names of the formal parameters

can be any valid identiﬁer. For the previous RUN command:

argv[0] = MYPROG.MYGROUP.MYACCT

argv[1] = "STR1"

argv[2] = "STR2"

argv[3] = "STR3"

argv[4] = NULL

argc = 4

parm = 11

info = "STR1 STR2 STR3"

To include blanks within a single entry in the argv array, the following command: