Read from Terminal and Files

Warning

These functions are provided for legacy code support. When writing new code, consider using Python input-output equivalents.

xred()

Syntax:

var = h.xred(promptstring, default, min, max)

Description:

xred() reads a value from the standard input after printing promptstring on the console. The value read must be in the range min <= val <= max and the user will be prompted to enter another number if the value is not in that range. If the user types the Return key, the default value is used (if it is in the valid range).

---

getstr()

Syntax:

h.getstr(strvar)

h.getstr(strvar, 1)

Description:

getstr() reads a string up to and including the next newline from the file opened with the ropen() command (or the currently executing file or the standard input) and places it in its string variable argument. With a second arg equal to 1, getstr reads a single word starting at the next non-whitespace character up to but not including the following whitespace (similar to fscan).

Example:

###########################################
### create a file titled "file.dat" with: #
### hello                                 #
### world                                 #
###########################################

from neuron import h, gui

def r_open(ndat):
    h.ropen("file.dat")
    string = ""
    s = h.ref(string)
    x = []
    for i in range(ndat):
        h.getstr(s, 1)
        x.append(s[0])
    h.ropen()
    return x

# ndat is number of data points
ndat = 2
x = r_open(ndat)
print x

See also

StringFunctions, sscanf(), File

---

sred()

Syntax:

index = h.sred(prompt, defaultchar, charlist)

Description:

sred() reads a character typed on the standard input after printing the first argument followed by the default character. The user is required to enter one of the characters in the character list (or return if the default happens to be one of these characters). The function returns the index in the character list of the character typed. The index of the first character is 0. The character accepted becomes the next default when this statement is executed again. This function was contributed by Stewart Jaslove.

Example:

from neuron import h, gui

def response(answer):
    if (answer == 0):
        print "No"
    else:
        print "Yes"

i = 0
while i == 0:
    i = h.sred("Shall we?", "y", "ny")
    response(i)

---

fscan()

Syntax:

var = h.scan()

Description:

fscan() reads the next number from the file opened with the ropen() command. If no file is opened the number is read from the currently executing file. If no file is being executed the number is read from the standard input. A number is scanned as long as it begins with a digit, decimal point, or sign. There can be more than one number per line but they must be set apart from each other by spaces or tabs. Strings that can't be scanned into numbers are skipped.

Example:

Suppose in response to the HOC command: print fscan(), fscan() the user types: this is a number 1.3e4 this is not45 this is 25 Then HOC will print: 13000 25

###########################################
### create a file titled "file.dat" with: #
### 42 13.7                               #
### 14 64.1                               #
### 12 9                                  #
###########################################

from neuron import h, gui

def r_open(ndat):
    h.ropen("file.dat")
    x = []
    y = []
    for i in range(ndat):
        x.append(h.fscan())
        y.append(h.fscan())
        h.ropen()
    return x, y

# ndat is number of data points
ndat = 3
x, y = r_open(ndat)

Diagnostics:

fscan() and getstr() returns to the HOC interpreter with a run-time error on EOF.

These functions are provided for legacy code support. In Python, it only supports file input not terminal input.

When writing new code, consider using Python input-output equivalents.

See also

File.scanvar(), read, File.ropen(), File(), sscanf(), StringFunctions, getstr()